Magnetite (Fe3O4) nanoparticles have garnered significant attention due to their small size and high surface area, biocompatibility, and magnetic properties. This review offers an insightful and comprehensive discussion of recent advances in synthesis techniques and their impact on nanoparticle formation and characteristics. The diverse applications of Fe3O4 nanoparticles in medicine, modern photonics, energy storage, biosensing, catalysis, and environmental remediation are examined. Additionally, surface functionalization strategies designed to enhance stability, biocompatibility, and application-specific reactivity are outlined. Finally, current limitations are discussed with an outline for future research directions along with concluding perspectives on the continued development of Fe3O4 nanoparticle technologies.
{"title":"Engineering magnetite (Fe3O4) nanoparticles: Controlled synthesis, surface functionalization, and multidisciplinary technological applications: A Review","authors":"Mahendra Kohale , Himanshu Inamdar , Kiran Kokate , Raju Ingale , Jayant Joshi , Deobrat Singh , Aavishkar Katti , Satish Polshettiwar , Rahul Aher , Sachin Kulkarni","doi":"10.1016/j.pcrysgrow.2026.100698","DOIUrl":"10.1016/j.pcrysgrow.2026.100698","url":null,"abstract":"<div><div>Magnetite (Fe<sub>3</sub>O<sub>4</sub>) nanoparticles have garnered significant attention due to their small size and high surface area, biocompatibility, and magnetic properties. This review offers an insightful and comprehensive discussion of recent advances in synthesis techniques and their impact on nanoparticle formation and characteristics. The diverse applications of Fe<sub>3</sub>O<sub>4</sub> nanoparticles in medicine, modern photonics, energy storage, biosensing, catalysis, and environmental remediation are examined. Additionally, surface functionalization strategies designed to enhance stability, biocompatibility, and application-specific reactivity are outlined. Finally, current limitations are discussed with an outline for future research directions along with concluding perspectives on the continued development of Fe<sub>3</sub>O<sub>4</sub> nanoparticle technologies.</div></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"72 1","pages":"Article 100698"},"PeriodicalIF":1.9,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01DOI: 10.1016/j.pcrysgrow.2025.100689
M. Petkovic, L. Vieira, N. Dropka
Machine learning (ML) has become an increasingly powerful tool in crystal growth research, enabling new ways to model processes, optimize growth conditions, and automate characterization of crystalline materials. This review provides a comprehensive overview of ML applications in the growth of semiconductors and electronic materials, covering both bulk crystal growth techniques (Czochralski, Floating Zone, Directional Solidification, Top Seed Solution Growth, etc.) and epitaxial growth methods (MOCVD, MOVPE, etc.), along with related characterization methods (photoluminescence imaging, X-ray diffraction, microscopy, etc.). We trace the historical development of ML in crystal growth and highlight recent advances such as deep learning for defect detection, surrogate modeling for process optimization, and reinforcement learning for autonomous control. Key ML methodologies (e.g., decision trees, neural networks, Gaussian processes, and generative models) are discussed in the context of crystal growth tasks like property prediction, defect classification, clustering of microstructural features, process optimization, and more. We also detail how various data sources, from in situ sensor readings and furnace design parameters (e.g., geometry and materials), to process simulations and ex situ characterization data, can be integrated into ML frameworks for prediction, optimization, and control. Challenges specific to crystal growth (limited data, data heterogeneity, integration with physical models, and others) are examined, and we outline emerging trends and future outlook, including physics-informed ML and digital twin approaches for crystal growth. Overall, this work aims to demonstrate the significant progress achieved at the intersection of ML and crystal growth, while providing guidance for future research in this rapidly evolving interdisciplinary field.
{"title":"Machine learning in crystal growth: A review of methods, data, and applications","authors":"M. Petkovic, L. Vieira, N. Dropka","doi":"10.1016/j.pcrysgrow.2025.100689","DOIUrl":"10.1016/j.pcrysgrow.2025.100689","url":null,"abstract":"<div><div>Machine learning (ML) has become an increasingly powerful tool in crystal growth research, enabling new ways to model processes, optimize growth conditions, and automate characterization of crystalline materials. This review provides a comprehensive overview of ML applications in the growth of semiconductors and electronic materials, covering both bulk crystal growth techniques (Czochralski, Floating Zone, Directional Solidification, Top Seed Solution Growth, etc.) and epitaxial growth methods (MOCVD, MOVPE, etc.), along with related characterization methods (photoluminescence imaging, X-ray diffraction, microscopy, etc.). We trace the historical development of ML in crystal growth and highlight recent advances such as deep learning for defect detection, surrogate modeling for process optimization, and reinforcement learning for autonomous control. Key ML methodologies (e.g., decision trees, neural networks, Gaussian processes, and generative models) are discussed in the context of crystal growth tasks like property prediction, defect classification, clustering of microstructural features, process optimization, and more. We also detail how various data sources, from in situ sensor readings and furnace design parameters (e.g., geometry and materials), to process simulations and ex situ characterization data, can be integrated into ML frameworks for prediction, optimization, and control. Challenges specific to crystal growth (limited data, data heterogeneity, integration with physical models, and others) are examined, and we outline emerging trends and future outlook, including physics-informed ML and digital twin approaches for crystal growth. Overall, this work aims to demonstrate the significant progress achieved at the intersection of ML and crystal growth, while providing guidance for future research in this rapidly evolving interdisciplinary field.</div></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"71 4","pages":"Article 100689"},"PeriodicalIF":1.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145568841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-13DOI: 10.1016/j.pcrysgrow.2025.100688
Yan Huang , Xuefeng Xiao , Xu Han , Jiahao Li , Yan Zhang , Jiashun Si , Shuaijie Liang , Qingyan Xu , Huan Zhang , Lingling Ma , Cui Yang , Xuefeng Zhang
Doped sapphire crystals (e.g., Ti: Al₂O₃, Cr: Al₂O₃, C: Al₂O₃, etc.), with their excellent physicochemical properties and tunable optoelectronic properties, are of great value for applications in the fields of laser devices, radiation detectors, and pyroelectric devices. In this paper, we systematically review the defect structures, preparation methods, and the modulation of the properties of different doped sapphire crystals, focus on the modulation mechanisms of different doping elements on the optical, mechanical, and laser properties of sapphire, and also details their optoelectronic applications in devices such as lasers, radiation detectors, and pyroelectric components. In addition, based on the current research progress, this paper also looks forward to the future development direction of doped sapphire crystals, including the optimization of the preparation technology for large-size and high-concentration uniformly doped crystals, as well as the potential for applications in emerging fields such as photonic chips and high-energy physics detectors, in anticipation of growing higher-quality doped sapphire crystals through the comprehensive improvement of the preparation technology and other aspects of the laser devices (e.g. photonic computing, LIDAR and other key hardware for artificial intelligence) and other applications.
{"title":"Properties of doped sapphire crystals and their optoelectronic applications","authors":"Yan Huang , Xuefeng Xiao , Xu Han , Jiahao Li , Yan Zhang , Jiashun Si , Shuaijie Liang , Qingyan Xu , Huan Zhang , Lingling Ma , Cui Yang , Xuefeng Zhang","doi":"10.1016/j.pcrysgrow.2025.100688","DOIUrl":"10.1016/j.pcrysgrow.2025.100688","url":null,"abstract":"<div><div>Doped sapphire crystals (e.g., Ti: Al₂O₃, Cr: Al₂O₃, C: Al₂O₃, etc.), with their excellent physicochemical properties and tunable optoelectronic properties, are of great value for applications in the fields of laser devices, radiation detectors, and pyroelectric devices. In this paper, we systematically review the defect structures, preparation methods, and the modulation of the properties of different doped sapphire crystals, focus on the modulation mechanisms of different doping elements on the optical, mechanical, and laser properties of sapphire, and also details their optoelectronic applications in devices such as lasers, radiation detectors, and pyroelectric components. In addition, based on the current research progress, this paper also looks forward to the future development direction of doped sapphire crystals, including the optimization of the preparation technology for large-size and high-concentration uniformly doped crystals, as well as the potential for applications in emerging fields such as photonic chips and high-energy physics detectors, in anticipation of growing higher-quality doped sapphire crystals through the comprehensive improvement of the preparation technology and other aspects of the laser devices (e.g. photonic computing, LIDAR and other key hardware for artificial intelligence) and other applications.</div></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"71 4","pages":"Article 100688"},"PeriodicalIF":1.9,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-10DOI: 10.1016/j.pcrysgrow.2025.100687
Anton P. Novikov, Mikhail A. Volkov
A targeted survey of structural databases, particularly focusing on salts of organic perrhenates, pertechnetates, and permanganates reveals that these tetrahedral anions (MO₄) form a variety of notable supramolecular synthons. These anions can assume diverse roles within the crystal structures. This review provides a detailed analysis of known organic and some selected inorganic salts and complexes containing such tetrahedral anions, identifying several previously overlooked subtypes of suprastructures. These suprastructures are classified into four categories based on their non-covalent contacts: clusters, polymers, networks, and framework. Our analysis demonstrates that tetrahedral anions are capable of forming 55 distinct structural motifs through non-covalent interactions in both organic and inorganic crystals, which can be categorized into 24 types of bonding interactions. We introduce the concept of denticity of the tetrahedron and its central atom within superstructures. Additionally, a brief statistical analysis of anion–anion non-covalent interactions in compounds of the manganese subgroup is presented.
{"title":"Non-covalent interactions of 7th group and tetrahedral anions","authors":"Anton P. Novikov, Mikhail A. Volkov","doi":"10.1016/j.pcrysgrow.2025.100687","DOIUrl":"10.1016/j.pcrysgrow.2025.100687","url":null,"abstract":"<div><div>A targeted survey of structural databases, particularly focusing on salts of organic perrhenates, pertechnetates, and permanganates reveals that these tetrahedral anions (MO₄) form a variety of notable supramolecular synthons. These anions can assume diverse roles within the crystal structures. This review provides a detailed analysis of known organic and some selected inorganic salts and complexes containing such tetrahedral anions, identifying several previously overlooked subtypes of suprastructures. These suprastructures are classified into four categories based on their non-covalent contacts: clusters, polymers, networks, and framework. Our analysis demonstrates that tetrahedral anions are capable of forming 55 distinct structural motifs through non-covalent interactions in both organic and inorganic crystals, which can be categorized into 24 types of bonding interactions. We introduce the concept of <em>denticity</em> of the tetrahedron and its central atom within superstructures. Additionally, a brief statistical analysis of anion–anion non-covalent interactions in compounds of the manganese subgroup is presented.</div></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"71 4","pages":"Article 100687"},"PeriodicalIF":1.9,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145265081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-07DOI: 10.1016/j.pcrysgrow.2025.100676
B.Sudarshan Acharya, Abdul Ajees Abdul Salam
X-ray crystallography remains the gold standard for resolving high-resolution atomic structures of biomolecules. Its unparalleled precision continues to provide critical structural insights that drive advances in drug discovery, enzyme mechanism elucidation, and molecular engineering across biotechnology, materials science, and nanomedicine. Despite its strengths, its success is fundamentally limited by the requirement for high-quality, well-ordered crystals, a persistent bottleneck in structural biology. Crystallization begins with nucleation, the critical step where solute molecules organize into a stable nucleus capable of initiating crystal growth. Controlling nucleation is essential for improving crystal reproducibility, size, and diffraction quality. To overcome this challenge, various interfaces, including liquid/liquid, air/water, and solid/liquid, have been explored, with the solid/liquid interface gaining increasing attention due to its ability to promote and modulate nucleation events. This review systematically discusses strategies utilizing solid/liquid interfaces to enhance protein crystallization efficiency and quality. It emphasizes the roles of diverse surfaces, including porous, hydrophobic, charged, rough, and functionalized substrates, and additive-assisted nucleation using micro-/macroparticles, nanoparticles, and DNA. Both electrostatic and non-electrostatic surface-induced mechanisms are critically analysed, with mechanistic insights into how these surfaces influence nucleation kinetics and crystal growth mechanisms. Comparative evaluations of different surface and additive systems are presented to identify effective nucleation enhancers and promote rational crystallization design. By deepening our understanding of interface-mediated nucleation and growth, this review provides a comprehensive knowledge base to support the rational development of reproducible, high-throughput crystallization strategies and outlines future directions for innovation in structural biology and crystallization science.
{"title":"Solid/liquid interface induced protein crystallization","authors":"B.Sudarshan Acharya, Abdul Ajees Abdul Salam","doi":"10.1016/j.pcrysgrow.2025.100676","DOIUrl":"10.1016/j.pcrysgrow.2025.100676","url":null,"abstract":"<div><div>X-ray crystallography remains the gold standard for resolving high-resolution atomic structures of biomolecules. Its unparalleled precision continues to provide critical structural insights that drive advances in drug discovery, enzyme mechanism elucidation, and molecular engineering across biotechnology, materials science, and nanomedicine. Despite its strengths, its success is fundamentally limited by the requirement for high-quality, well-ordered crystals, a persistent bottleneck in structural biology. Crystallization begins with nucleation, the critical step where solute molecules organize into a stable nucleus capable of initiating crystal growth. Controlling nucleation is essential for improving crystal reproducibility, size, and diffraction quality. To overcome this challenge, various interfaces, including liquid/liquid, air/water, and solid/liquid, have been explored, with the solid/liquid interface gaining increasing attention due to its ability to promote and modulate nucleation events. This review systematically discusses strategies utilizing solid/liquid interfaces to enhance protein crystallization efficiency and quality. It emphasizes the roles of diverse surfaces, including porous, hydrophobic, charged, rough, and functionalized substrates, and additive-assisted nucleation using micro-/macroparticles, nanoparticles, and DNA. Both electrostatic and non-electrostatic surface-induced mechanisms are critically analysed, with mechanistic insights into how these surfaces influence nucleation kinetics and crystal growth mechanisms. Comparative evaluations of different surface and additive systems are presented to identify effective nucleation enhancers and promote rational crystallization design. By deepening our understanding of interface-mediated nucleation and growth, this review provides a comprehensive knowledge base to support the rational development of reproducible, high-throughput crystallization strategies and outlines future directions for innovation in structural biology and crystallization science.</div></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"71 3","pages":"Article 100676"},"PeriodicalIF":4.5,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144571161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-08DOI: 10.1016/j.pcrysgrow.2025.100668
Lutz Kirste , Thu Nhi Tran-Caliste , Tomasz Sochacki , Jan L. Weyher , Patrik Straňák , Robert Kucharski , Karolina Grabianska , José Baruchel , Michal Bockowski
We investigate the defect structure of gallium nitride (GaN) substrates grown by hydride vapor phase epitaxy (HVPE) and ammonothermal method, with emphasis on the seeding approach (“foreign seed” or “native seed”). X-ray Bragg diffraction imaging techniques (laboratory X-ray Lang topography (L-XRT) and synchrotron monochromatic rocking curve imaging (RCI)) were used to study the defects of the GaN substrates. The efficiency of the in-process L-XRT method, whereas being strongly dependent on the structural perfection of the crystals, is important because it provides a good overview of the defect structure for entire substrates. But it remains qualitative, or semi-quantitative. RCI, on the other hand, allows obtaining complete quantitative information about lattice misorientation and distortion with sub-µm resolution. The contrast of the diffraction images of defects such as grain boundaries, dislocations, dislocation bundles, planar defects and others, is discussed, with emphasis on the influence of threading dislocation density on the contrast of the Bragg diffraction imaging. We complemented the diffraction studies with defect selective etching analyses and, to determine the level of impurities in the GaN substrates, by time-of-flight secondary ion mass spectrometry (ToF-SIMS). The main finding of this study is that a native seed approach is essential for crystallizing GaN with high structural perfection and low threading dislocation density. This is true whether the GaN crystals are grown by HVPE or ammonothermal methods. A potential route to low-defect, low-impurity GaN substrates is outlined as a fundamental element for realizing GaN-based devices with high performance, life-time, and reliability.
{"title":"Bragg diffraction imaging characterization of crystal defects in GaN (0001) substrates: Comparison of the growth method and the seed approach","authors":"Lutz Kirste , Thu Nhi Tran-Caliste , Tomasz Sochacki , Jan L. Weyher , Patrik Straňák , Robert Kucharski , Karolina Grabianska , José Baruchel , Michal Bockowski","doi":"10.1016/j.pcrysgrow.2025.100668","DOIUrl":"10.1016/j.pcrysgrow.2025.100668","url":null,"abstract":"<div><div>We investigate the defect structure of gallium nitride (GaN) substrates grown by hydride vapor phase epitaxy (HVPE) and ammonothermal method, with emphasis on the seeding approach (“foreign seed” or “native seed”). X-ray Bragg diffraction imaging techniques (laboratory X-ray Lang topography (L-XRT) and synchrotron monochromatic rocking curve imaging (RCI)) were used to study the defects of the GaN substrates. The efficiency of the in-process L-XRT method, whereas being strongly dependent on the structural perfection of the crystals, is important because it provides a good overview of the defect structure for entire substrates. But it remains qualitative, or semi-quantitative. RCI, on the other hand, allows obtaining complete quantitative information about lattice misorientation and distortion with sub-µm resolution. The contrast of the diffraction images of defects such as grain boundaries, dislocations, dislocation bundles, planar defects and others, is discussed, with emphasis on the influence of threading dislocation density on the contrast of the Bragg diffraction imaging. We complemented the diffraction studies with defect selective etching analyses and, to determine the level of impurities in the GaN substrates, by time-of-flight secondary ion mass spectrometry (ToF-SIMS). The main finding of this study is that a native seed approach is essential for crystallizing GaN with high structural perfection and low threading dislocation density. This is true whether the GaN crystals are grown by HVPE or ammonothermal methods. A potential route to low-defect, low-impurity GaN substrates is outlined as a fundamental element for realizing GaN-based devices with high performance, life-time, and reliability.</div></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"71 3","pages":"Article 100668"},"PeriodicalIF":4.5,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143922050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-26DOI: 10.1016/j.pcrysgrow.2025.100667
Kristin Kliemt
This work provides a review of crystal growth, crystal structure, compositional details, magnetism, thermodynamic, and transport behavior in the family of the trigonal intermetallic systems Eu ( Cd, Zn; P, As, Sb; space group , No. 164). The physical properties observed in these materials, and how these change depending on the growth conditions are discussed. In particular, the case of EuCdAs is considered where data from many sources are available. The possible small contamination of the material during crystal growth experiments is hard to verify as it is often below the detection limit of the standard characterization techniques. It turns out that samples from different sources exhibit variations in the lattice parameters exceeding the experimental errors. The review of these parameters reveals that they are very similar for antiferromagnetic samples grown from Sn flux in AlO crucibles, while there is a wider spread for samples grown from salt flux grown in SiO2 ampules, which are mostly ferromagnetic. The influence of the different experimental setups with regard to possible impurities in the samples is discussed.
{"title":"Chemical pressure due to impurities in trigonal compounds EuT2Pn2 (T= Cd, Zn; Pn= P, As, Sb)","authors":"Kristin Kliemt","doi":"10.1016/j.pcrysgrow.2025.100667","DOIUrl":"10.1016/j.pcrysgrow.2025.100667","url":null,"abstract":"<div><div>This work provides a review of crystal growth, crystal structure, compositional details, magnetism, thermodynamic, and transport behavior in the family of the trigonal intermetallic systems Eu<span><math><mrow><msub><mrow><mi>T</mi></mrow><mrow><mn>2</mn></mrow></msub><mi>P</mi><msub><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> (<span><math><mrow><mi>T</mi><mo>=</mo></mrow></math></span> Cd, Zn; <span><math><mrow><mi>P</mi><mi>n</mi><mo>=</mo></mrow></math></span> P, As, Sb; space group <span><math><mrow><mi>P</mi><mover><mrow><mn>3</mn></mrow><mo>¯</mo></mover><mi>m</mi><mn>1</mn></mrow></math></span>, No. 164). The physical properties observed in these materials, and how these change depending on the growth conditions are discussed. In particular, the case of EuCd<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> is considered where data from many sources are available. The possible small contamination of the material during crystal growth experiments is hard to verify as it is often below the detection limit of the standard characterization techniques. It turns out that samples from different sources exhibit variations in the lattice parameters exceeding the experimental errors. The review of these parameters reveals that they are very similar for antiferromagnetic samples grown from Sn flux in Al<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> crucibles, while there is a wider spread for samples grown from salt flux grown in SiO<sub>2</sub> ampules, which are mostly ferromagnetic. The influence of the different experimental setups with regard to possible impurities in the samples is discussed.</div></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"71 2","pages":"Article 100667"},"PeriodicalIF":4.5,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143873961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-17DOI: 10.1016/j.pcrysgrow.2025.100666
Lingling Xuan, Thierry Duffar
<div><div>The main application of Ti doped sapphire (Ti:sapphire) lies in the field of lasers, thanks to its outstanding production of ultra-short pulses due to the presence of doping Ti<sup>3+</sup> ions. The absorption and emission mechanisms of this crystal are intricate, necessitating consideration of point defects existing in the grown crystal. A plethora of liquid-phase growth methods yield crystals of diverse sizes and quality. This paper gives a comprehensive review of the literature on managing dopants during the growth of Ti doped bulk sapphire crystals.</div><div>Substantial research has indicated that the presence of detrimental Ti<sup>4+</sup> ions diminishes the crystal laser efficiency due to their residual absorption. Although annealing under reducing atmosphere is an efficient way to increase the Ti<sup>3+</sup>/Ti<sup>4+</sup> ratio, this process becomes increasingly time-consuming as the demand for larger optical components increases. Consequently, it would be more practical and convenient to control this ratio directly during the growth processes. However, the conversion mechanisms between the two Ti ions valences during crystal growth and annealing remain largely unexplored.</div><div>A study of the thermodynamics of the Al<sub>2</sub>O<sub>3</sub>/TiO<sub>2</sub> and Al<sub>2</sub>O<sub>3</sub>/Ti<sub>2</sub>O<sub>3</sub> solid and liquid solutions as a function of the partial pressure (<span><math><msub><mi>p</mi><msub><mi>O</mi><mn>2</mn></msub></msub></math></span>) and oxygen activity is crucial for understanding these mechanisms. This paper presents corrected, reliable phase diagrams that enable quantitative prediction of the effect of <span><math><msub><mi>p</mi><msub><mi>O</mi><mn>2</mn></msub></msub></math></span> on the melt concentrations of the two ions. Consequently, a novel value of the absorption coefficient constant, pertinent to Ti<sup>4+</sup> concentration measurement, is proposed. Equilibrium with the solid solution yields segregation coefficients that appear distinct for the two ions. Given their influence on oxygen activity during growth, the effect of surrounding furnace parts, such as graphite casing or Mo crucible, is also important.</div><div>Understanding the behavior of Ti<sup>3+</sup>and Ti<sup>4+</sup> ions in the grown crystal as a function of pulling time and considering the <span><math><msub><mi>p</mi><msub><mi>O</mi><mn>2</mn></msub></msub></math></span> levels in the furnace atmosphere, requires the knowledge of solid-state electrochemistry, including the charge carriers and the Al and O vacancies. This foundation allows the development of a physico-chemical model illustrating the evolution of ion valence during growth. Analysis of experimental results from existing literature gives the necessary diffusion coefficients and reaction rate constants. Investigating crystal-atmosphere interaction provides the required boundary condition for solving the problem. The findings exhibit qualitative ag
{"title":"The growth of titanium doped sapphire for laser application","authors":"Lingling Xuan, Thierry Duffar","doi":"10.1016/j.pcrysgrow.2025.100666","DOIUrl":"10.1016/j.pcrysgrow.2025.100666","url":null,"abstract":"<div><div>The main application of Ti doped sapphire (Ti:sapphire) lies in the field of lasers, thanks to its outstanding production of ultra-short pulses due to the presence of doping Ti<sup>3+</sup> ions. The absorption and emission mechanisms of this crystal are intricate, necessitating consideration of point defects existing in the grown crystal. A plethora of liquid-phase growth methods yield crystals of diverse sizes and quality. This paper gives a comprehensive review of the literature on managing dopants during the growth of Ti doped bulk sapphire crystals.</div><div>Substantial research has indicated that the presence of detrimental Ti<sup>4+</sup> ions diminishes the crystal laser efficiency due to their residual absorption. Although annealing under reducing atmosphere is an efficient way to increase the Ti<sup>3+</sup>/Ti<sup>4+</sup> ratio, this process becomes increasingly time-consuming as the demand for larger optical components increases. Consequently, it would be more practical and convenient to control this ratio directly during the growth processes. However, the conversion mechanisms between the two Ti ions valences during crystal growth and annealing remain largely unexplored.</div><div>A study of the thermodynamics of the Al<sub>2</sub>O<sub>3</sub>/TiO<sub>2</sub> and Al<sub>2</sub>O<sub>3</sub>/Ti<sub>2</sub>O<sub>3</sub> solid and liquid solutions as a function of the partial pressure (<span><math><msub><mi>p</mi><msub><mi>O</mi><mn>2</mn></msub></msub></math></span>) and oxygen activity is crucial for understanding these mechanisms. This paper presents corrected, reliable phase diagrams that enable quantitative prediction of the effect of <span><math><msub><mi>p</mi><msub><mi>O</mi><mn>2</mn></msub></msub></math></span> on the melt concentrations of the two ions. Consequently, a novel value of the absorption coefficient constant, pertinent to Ti<sup>4+</sup> concentration measurement, is proposed. Equilibrium with the solid solution yields segregation coefficients that appear distinct for the two ions. Given their influence on oxygen activity during growth, the effect of surrounding furnace parts, such as graphite casing or Mo crucible, is also important.</div><div>Understanding the behavior of Ti<sup>3+</sup>and Ti<sup>4+</sup> ions in the grown crystal as a function of pulling time and considering the <span><math><msub><mi>p</mi><msub><mi>O</mi><mn>2</mn></msub></msub></math></span> levels in the furnace atmosphere, requires the knowledge of solid-state electrochemistry, including the charge carriers and the Al and O vacancies. This foundation allows the development of a physico-chemical model illustrating the evolution of ion valence during growth. Analysis of experimental results from existing literature gives the necessary diffusion coefficients and reaction rate constants. Investigating crystal-atmosphere interaction provides the required boundary condition for solving the problem. The findings exhibit qualitative ag","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"71 2","pages":"Article 100666"},"PeriodicalIF":4.5,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-07DOI: 10.1016/j.pcrysgrow.2025.100665
P. Atheek , P. Puviarasu , S. Munawar Basha , G. Balaji
Gallium Nitride (GaN) materials have unique electronic, optical, and mechanical properties that make them useful for various applications. However, these materials have complex structures and behavior, making it challenging to characterize them. Micro-Raman spectroscopy (MRS) is an appreciatively effective and adaptable method for analyzing the different properties of GaN materials, such as stress, strain, carrier concentration, and phonon lifetime. This review article provides an overview of the principles of MRS and its applications in GaN material characterization. The behavior of vibration modes of GaN material depends on the defects in the epilayer which alters the materials physical properties, such as stress and strain. The A1(LO) vibration mode of longitudinal optical phonons provides information on electrical properties, such as carrier concentration and phonon lifetime. This review explains the MRS use in quantifying the physical and electrical properties of GaN materials over other characterization.
{"title":"Role of micro-Raman technique in material characterization of GaN wide bandgap semiconductor: Review","authors":"P. Atheek , P. Puviarasu , S. Munawar Basha , G. Balaji","doi":"10.1016/j.pcrysgrow.2025.100665","DOIUrl":"10.1016/j.pcrysgrow.2025.100665","url":null,"abstract":"<div><div>Gallium Nitride (GaN) materials have unique electronic, optical, and mechanical properties that make them useful for various applications. However, these materials have complex structures and behavior, making it challenging to characterize them. Micro-Raman spectroscopy (MRS) is an appreciatively effective and adaptable method for analyzing the different properties of GaN materials, such as stress, strain, carrier concentration, and phonon lifetime. This review article provides an overview of the principles of MRS and its applications in GaN material characterization. The behavior of <span><math><msubsup><mi>E</mi><mn>2</mn><mi>H</mi></msubsup></math></span> vibration modes of GaN material depends on the defects in the epilayer which alters the materials physical properties, such as stress and strain. The A<sub>1</sub>(LO) vibration mode of longitudinal optical phonons provides information on electrical properties, such as carrier concentration and phonon lifetime. This review explains the MRS use in quantifying the physical and electrical properties of GaN materials over other characterization.</div></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"71 2","pages":"Article 100665"},"PeriodicalIF":4.5,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-21DOI: 10.1016/j.pcrysgrow.2024.100658
Mujie Xu , Zining Wang , Rui Wang , Zhihong Yu , Zhenhao Sun , Bo Fu , Yujun Shi
High-quality crystals commonly exhibit regular morphology features and symmetries related to their crystal structures. The recognition of morphology features, especially on the shoulder morphology, will provide crucial guidance for the crystal growth and quality control. Here, the morphology features of β-Ga2O3 bulk crystals were discussed from three aspects of growth technology, orientation of seed crystal as well as pulling and rotation rates. Combined with the theoretical morphology of β-Ga2O3 crystal, the morphology features of β-Ga2O3 bulk crystals under different growth conditions were illuminated and summarized. The hexagonal seed crystal was also demonstrated, and more suitable for the growth of β-Ga2O3 bulk crystals with different principle surfaces by EFG method. The first review in the morphology features will become an important reference for future research on the growth of β-Ga2O3 bulk crystals.
{"title":"Morphology features of β-Ga2O3 bulk crystals by EFG and CZ methods: A review","authors":"Mujie Xu , Zining Wang , Rui Wang , Zhihong Yu , Zhenhao Sun , Bo Fu , Yujun Shi","doi":"10.1016/j.pcrysgrow.2024.100658","DOIUrl":"10.1016/j.pcrysgrow.2024.100658","url":null,"abstract":"<div><div>High-quality crystals commonly exhibit regular morphology features and symmetries related to their crystal structures. The recognition of morphology features, especially on the shoulder morphology, will provide crucial guidance for the crystal growth and quality control. Here, the morphology features of <em>β</em>-Ga<sub>2</sub>O<sub>3</sub> bulk crystals were discussed from three aspects of growth technology, orientation of seed crystal as well as pulling and rotation rates. Combined with the theoretical morphology of <em>β</em>-Ga<sub>2</sub>O<sub>3</sub> crystal, the morphology features of <em>β</em>-Ga<sub>2</sub>O<sub>3</sub> bulk crystals under different growth conditions were illuminated and summarized. The hexagonal seed crystal was also demonstrated, and more suitable for the growth of <em>β</em>-Ga<sub>2</sub>O<sub>3</sub> bulk crystals with different principle surfaces by EFG method. The first review in the morphology features will become an important reference for future research on the growth of <em>β</em>-Ga<sub>2</sub>O<sub>3</sub> bulk crystals.</div></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"71 1","pages":"Article 100658"},"PeriodicalIF":4.5,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143163710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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