Pub Date : 2019-12-03DOI: 10.1080/07315171.2019.1668684
Raghavendra Sagar, R. Raibagkar
Abstract The microstructure, dielectric and pyroelectric properties of pure and Gd3+- doped barium zirconium titanate in the form of Ba(Zr0.52Ti0.48)O3 and (Ba1-xGdx)(Zr0.52Ti0.48)O3 (x = 0.1 and 0.2) were studied in this work. These ceramics were synthesized from solid state reaction method at 1050 °C. The patterns obtained from x-ray diffraction revealed the formation of perovskite phase with tetragonal crystal symmetry. As the concentration of Gd-ion increased, the value of temperature dependent dielectric constant varied whereas the Curie temperature of the ceramics shifted towards higher temperature side. The ceramic sample doped with Gd = 0.1 exhibited diffuse phase transition whereas other one showed relaxor like behavior. This result is attributed to unsystematic decrease in average grain size due to doping of Gd-ions. The temperature dependent pyroelectric current was negative at ∼150 °C for pure ceramics and at ∼200 °C for Gd-doped ceramics. This negative pyroelectric current represents the primary pyroelectric effect within that temperature.
{"title":"Effect of gadolinium on the dielectric and pyroelectric behavior of Ba(Zr0.52Ti0.48)O3 ceramics","authors":"Raghavendra Sagar, R. Raibagkar","doi":"10.1080/07315171.2019.1668684","DOIUrl":"https://doi.org/10.1080/07315171.2019.1668684","url":null,"abstract":"Abstract The microstructure, dielectric and pyroelectric properties of pure and Gd3+- doped barium zirconium titanate in the form of Ba(Zr0.52Ti0.48)O3 and (Ba1-xGdx)(Zr0.52Ti0.48)O3 (x = 0.1 and 0.2) were studied in this work. These ceramics were synthesized from solid state reaction method at 1050 °C. The patterns obtained from x-ray diffraction revealed the formation of perovskite phase with tetragonal crystal symmetry. As the concentration of Gd-ion increased, the value of temperature dependent dielectric constant varied whereas the Curie temperature of the ceramics shifted towards higher temperature side. The ceramic sample doped with Gd = 0.1 exhibited diffuse phase transition whereas other one showed relaxor like behavior. This result is attributed to unsystematic decrease in average grain size due to doping of Gd-ions. The temperature dependent pyroelectric current was negative at ∼150 °C for pure ceramics and at ∼200 °C for Gd-doped ceramics. This negative pyroelectric current represents the primary pyroelectric effect within that temperature.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"159 4 1","pages":"106 - 99"},"PeriodicalIF":0.4,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73685605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-03DOI: 10.1080/07315171.2019.1668685
S. Ai, Shao-yin Zhang, Yuan-Zhen Cai
Abstract The differences between demagnetization fields and depolarization fields were compared. The most fundamental reason is the existence of electric charges but the nonexistence of magnetic charges. For ferroics (ferromagnetics and ferroelectrics), the non-equilibrium thermodynamics of phase transitions was considered and the conclusion remains the same.
{"title":"A discussion: comparison of demagnetization fields and depolarization fields","authors":"S. Ai, Shao-yin Zhang, Yuan-Zhen Cai","doi":"10.1080/07315171.2019.1668685","DOIUrl":"https://doi.org/10.1080/07315171.2019.1668685","url":null,"abstract":"Abstract The differences between demagnetization fields and depolarization fields were compared. The most fundamental reason is the existence of electric charges but the nonexistence of magnetic charges. For ferroics (ferromagnetics and ferroelectrics), the non-equilibrium thermodynamics of phase transitions was considered and the conclusion remains the same.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"56 1","pages":"107 - 110"},"PeriodicalIF":0.4,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86966648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-28DOI: 10.1080/07315171.2019.1647722
Baljinder Kaur, Lakhbir Singh, T. Garg, D. Jeong, N. Dabra, J. Hundal
Abstract Single phase Bi2Fe4O9 (Mullite BFO) nanoparticles were prepared first time by combustion method without using any solvent. Metal nitrates as oxidants and citric acid as fuel was used to synthesize Bi2Fe4O9 which were subsequently annealed at temperatures 550 °C, 600 °C and 650 °C. The impact of annealing temperature on crystal structure and physical properties are investigated by using X -ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Electron Dispersion Spectroscopy (EDS), Ultra Violet Visible (UV–vis) spectroscopic studies and Fourier Transformed Infrared Spectroscopy (FTIR). X-ray diffraction confirmed orthorhombic phase of the Mullite BFO and peak profile analysis has been carried out to study the crystallite development in Mullite BFO nanoparticles. The Mullite BFO annealed at 600 °C showed minimum lattice strain. Further, the FTIR and UV-Vis spectra of the samples at room temperature confirm the formation of orthorhombic structure of the samples. Our results revealed that the band gap of Mullite BFO nanoparticles reduces with increase in strain and lowest band gap attained for strained mullite BFO annealed at 650 °C is 2.0 eV. The correlation of annealing temperature with calculated lattice and structural parameter of Mullite BFO nanoparticles was established. Magnetic measurements were carried out at room temperature up to a field of 30 kOe. All samples of Mullite BFO showed weak ferromagnetic behavior. Magnetic hysteresis loops showed a significant increase in magnetization for sample annealed at 600 °C.
{"title":"A comparative investigation of structural and optical properties of annealing modified mullite bismuth ferrite","authors":"Baljinder Kaur, Lakhbir Singh, T. Garg, D. Jeong, N. Dabra, J. Hundal","doi":"10.1080/07315171.2019.1647722","DOIUrl":"https://doi.org/10.1080/07315171.2019.1647722","url":null,"abstract":"Abstract Single phase Bi2Fe4O9 (Mullite BFO) nanoparticles were prepared first time by combustion method without using any solvent. Metal nitrates as oxidants and citric acid as fuel was used to synthesize Bi2Fe4O9 which were subsequently annealed at temperatures 550 °C, 600 °C and 650 °C. The impact of annealing temperature on crystal structure and physical properties are investigated by using X -ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Electron Dispersion Spectroscopy (EDS), Ultra Violet Visible (UV–vis) spectroscopic studies and Fourier Transformed Infrared Spectroscopy (FTIR). X-ray diffraction confirmed orthorhombic phase of the Mullite BFO and peak profile analysis has been carried out to study the crystallite development in Mullite BFO nanoparticles. The Mullite BFO annealed at 600 °C showed minimum lattice strain. Further, the FTIR and UV-Vis spectra of the samples at room temperature confirm the formation of orthorhombic structure of the samples. Our results revealed that the band gap of Mullite BFO nanoparticles reduces with increase in strain and lowest band gap attained for strained mullite BFO annealed at 650 °C is 2.0 eV. The correlation of annealing temperature with calculated lattice and structural parameter of Mullite BFO nanoparticles was established. Magnetic measurements were carried out at room temperature up to a field of 30 kOe. All samples of Mullite BFO showed weak ferromagnetic behavior. Magnetic hysteresis loops showed a significant increase in magnetization for sample annealed at 600 °C.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"38 1","pages":"52 - 63"},"PeriodicalIF":0.4,"publicationDate":"2019-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77737280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-28DOI: 10.1080/07315171.2019.1647704
M. A. Barique, Y. Matsuda, Kazuma Matsuyama, S. Tasaka
Abstract Ferroelectric behavior was observed in the crystalline copolymers of vinylidene chloride (VDC) with vinylchloride (VC) and with methylacrylate (MA). A D-E hysteresis loop for P(VDC/VC) copolymer observed at above its glass transition temperature indicates the ferroelectricity of this copolymer. The remanent polarization was between 30 and 122 mC/m2, and pyroelectric constants of the copolymers was stable up to almost their melting points. The results of FTIR and XRD suggested that the electric behaviors of P(VDC/VC) copolymers were caused by the orientation of C-Cl dipoles in VDC chains in the crystal region to form a polar structure in a high electric field.
{"title":"Ferroelectric behavior in vinylidene chloride copolymers","authors":"M. A. Barique, Y. Matsuda, Kazuma Matsuyama, S. Tasaka","doi":"10.1080/07315171.2019.1647704","DOIUrl":"https://doi.org/10.1080/07315171.2019.1647704","url":null,"abstract":"Abstract Ferroelectric behavior was observed in the crystalline copolymers of vinylidene chloride (VDC) with vinylchloride (VC) and with methylacrylate (MA). A D-E hysteresis loop for P(VDC/VC) copolymer observed at above its glass transition temperature indicates the ferroelectricity of this copolymer. The remanent polarization was between 30 and 122 mC/m2, and pyroelectric constants of the copolymers was stable up to almost their melting points. The results of FTIR and XRD suggested that the electric behaviors of P(VDC/VC) copolymers were caused by the orientation of C-Cl dipoles in VDC chains in the crystal region to form a polar structure in a high electric field.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"2 1","pages":"1 - 7"},"PeriodicalIF":0.4,"publicationDate":"2019-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80268949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-28DOI: 10.1080/07315171.2019.1647718
S. Qu, Ganlin Chen, W. Cao, R. K. Pan, Y. Qi, Lei Zhang, Xunzhong Shang
Abstract Based on the Devonshire theory, the E-induced effects of polarization, dielectrics, hysteresis loop, and energy storage are investigated. Numerical simulations confirm that the ferroelectrics with soft ferroelectricity with properties of small and E-sensitive polarization, abrupt decrease of dielectric peak with increasing E, sloped and slender hysteresis loop with central narrow when approaching Tc, and symmetry energy storage peak, much less than Tc, towards high temperature with increasing E, can be the candidate of high energy storage materials. HIGHLIGHTS E-induced polarization effect is related with thermodynamic parameters of ferroelectrics. Peak of energy storage shifts to high temperature under high-E. Larger induced polarization is corresponding to higher energy storage.
{"title":"Influence of polarization effect by electric field on energy storage","authors":"S. Qu, Ganlin Chen, W. Cao, R. K. Pan, Y. Qi, Lei Zhang, Xunzhong Shang","doi":"10.1080/07315171.2019.1647718","DOIUrl":"https://doi.org/10.1080/07315171.2019.1647718","url":null,"abstract":"Abstract Based on the Devonshire theory, the E-induced effects of polarization, dielectrics, hysteresis loop, and energy storage are investigated. Numerical simulations confirm that the ferroelectrics with soft ferroelectricity with properties of small and E-sensitive polarization, abrupt decrease of dielectric peak with increasing E, sloped and slender hysteresis loop with central narrow when approaching Tc, and symmetry energy storage peak, much less than Tc, towards high temperature with increasing E, can be the candidate of high energy storage materials. HIGHLIGHTS E-induced polarization effect is related with thermodynamic parameters of ferroelectrics. Peak of energy storage shifts to high temperature under high-E. Larger induced polarization is corresponding to higher energy storage.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"109 1","pages":"30 - 37"},"PeriodicalIF":0.4,"publicationDate":"2019-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85574592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-28DOI: 10.1080/07315171.2019.1647719
Nayana Acharya, Raghavendra Sagar
Abstract In this paper, we report the influence of A-site substitution on dielectric and electrical behavior of Mn3O4 based modified spinels at room temperature. All the three spinels substituted with Mn, Zn and Co at A-site showed slight decrease in relative permittivity (ε′) and dissipation factor (tanδ) in the studied frequency range of 40 Hz to 8 MHz. However, the influence of A-site substitution was noticeable because of it dominant influence on relative permittivity and dissipation factor over pure Mn3O4 spinel. The relative permittivity increased from ∼ 16 to 95 after substitution of Zn in A-site whereas the substitution of Co increased the magnitude upto 40. Similar trend was observed with tan δ measurement after A-site substitution. The frequency dependent impedance measurement revealed the better conducting behavior of pure and modified spinels because of its low impedance range and better frequency dependent ac-conductivity.
{"title":"Influence of A-site substitution on dielectric and impedance behavior of Mn3O4 spinels","authors":"Nayana Acharya, Raghavendra Sagar","doi":"10.1080/07315171.2019.1647719","DOIUrl":"https://doi.org/10.1080/07315171.2019.1647719","url":null,"abstract":"Abstract In this paper, we report the influence of A-site substitution on dielectric and electrical behavior of Mn3O4 based modified spinels at room temperature. All the three spinels substituted with Mn, Zn and Co at A-site showed slight decrease in relative permittivity (ε′) and dissipation factor (tanδ) in the studied frequency range of 40 Hz to 8 MHz. However, the influence of A-site substitution was noticeable because of it dominant influence on relative permittivity and dissipation factor over pure Mn3O4 spinel. The relative permittivity increased from ∼ 16 to 95 after substitution of Zn in A-site whereas the substitution of Co increased the magnitude upto 40. Similar trend was observed with tan δ measurement after A-site substitution. The frequency dependent impedance measurement revealed the better conducting behavior of pure and modified spinels because of its low impedance range and better frequency dependent ac-conductivity.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"38 1","pages":"38 - 45"},"PeriodicalIF":0.4,"publicationDate":"2019-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86389385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-28DOI: 10.1080/07315171.2019.1647705
Mamta Shandilya, S. Thakur, R. Rai
Abstract Lead-free relaxor ferroelectric, Ba0.85Ca0.15Zr0.05Ti0.95O3 have been fabricated by a hydrothermal method. Single-phase X-ray diffraction patterns conforms very closely to perovskites structure and the samples have a phase with a tetragonal structure at room temperature. The FESEM image of Ba0.85Ca0.15Zr0.05Ti0.95O3 powder shows cylindrical like crystals. Small grains with average grain sizes of ∼10 ± 5 nm uniformly distributed all over the powder. The most intense diffraction rings from TEM correspond to large crystallites. A broad dielectric anomaly coupled with the dielectric maxima with increasing frequency indicates the second order diffuse phase transition in the system.
{"title":"Study of phase transitional behavior and electrical properties of relaxor Ba0.85Ca0.15Zr0.05Ti0.95O3 lead free ceramic","authors":"Mamta Shandilya, S. Thakur, R. Rai","doi":"10.1080/07315171.2019.1647705","DOIUrl":"https://doi.org/10.1080/07315171.2019.1647705","url":null,"abstract":"Abstract Lead-free relaxor ferroelectric, Ba0.85Ca0.15Zr0.05Ti0.95O3 have been fabricated by a hydrothermal method. Single-phase X-ray diffraction patterns conforms very closely to perovskites structure and the samples have a phase with a tetragonal structure at room temperature. The FESEM image of Ba0.85Ca0.15Zr0.05Ti0.95O3 powder shows cylindrical like crystals. Small grains with average grain sizes of ∼10 ± 5 nm uniformly distributed all over the powder. The most intense diffraction rings from TEM correspond to large crystallites. A broad dielectric anomaly coupled with the dielectric maxima with increasing frequency indicates the second order diffuse phase transition in the system.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"18 1","pages":"18 - 8"},"PeriodicalIF":0.4,"publicationDate":"2019-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85143669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-28DOI: 10.1080/07315171.2019.1647711
Jing Liu, Jianke Du, Ji Wang, Jia-shi Yang
Abstract We study free vibrations of thin-film bulk acoustic wave filters theoretically using the scalar differential equations by Tiersten and Stevens. The filters are made from piezoelectric crystal films of AlN or ZnO on Si substrates with interdigital ground and driving electrodes. They operate with thickness-extensional modes. Transversely varying modes with variations in both of the in-plane directions along and perpendicular to the electrodes are obtained, including both the device operating modes and unwanted modes which need to be predicted and avoided through design.
{"title":"Transversely varying thickness-extensional modes in thin film bulk acoustic wave piezoelectric filters with interdigital electrodes","authors":"Jing Liu, Jianke Du, Ji Wang, Jia-shi Yang","doi":"10.1080/07315171.2019.1647711","DOIUrl":"https://doi.org/10.1080/07315171.2019.1647711","url":null,"abstract":"Abstract We study free vibrations of thin-film bulk acoustic wave filters theoretically using the scalar differential equations by Tiersten and Stevens. The filters are made from piezoelectric crystal films of AlN or ZnO on Si substrates with interdigital ground and driving electrodes. They operate with thickness-extensional modes. Transversely varying modes with variations in both of the in-plane directions along and perpendicular to the electrodes are obtained, including both the device operating modes and unwanted modes which need to be predicted and avoided through design.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"16 1","pages":"19 - 29"},"PeriodicalIF":0.4,"publicationDate":"2019-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87269969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-28DOI: 10.1080/07315171.2019.1647720
S. Ai, Shao-yin Zhang
Abstract The equilibrium thermodynamic approach to ferroic hysteresis was recalled firstly, especially according to the ferroelectric case. Then based on the uniqueness of equilibrium state, it was showed that a ferroic hysteresis loop is composed of stationary states but not equilibrium ones, especially according to the ferromagnetic case. So, it was concluded that the equilibrium thermodynamic approach to ferroic hysteresis is not reliable. Life-force should be bestowed on the domain structure dynamic approach and the non-equilibrium thermodynamic approach.
{"title":"Comments on equilibrium thermodynamic approach to ferroic hysteresis","authors":"S. Ai, Shao-yin Zhang","doi":"10.1080/07315171.2019.1647720","DOIUrl":"https://doi.org/10.1080/07315171.2019.1647720","url":null,"abstract":"Abstract The equilibrium thermodynamic approach to ferroic hysteresis was recalled firstly, especially according to the ferroelectric case. Then based on the uniqueness of equilibrium state, it was showed that a ferroic hysteresis loop is composed of stationary states but not equilibrium ones, especially according to the ferromagnetic case. So, it was concluded that the equilibrium thermodynamic approach to ferroic hysteresis is not reliable. Life-force should be bestowed on the domain structure dynamic approach and the non-equilibrium thermodynamic approach.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"11 1","pages":"46 - 51"},"PeriodicalIF":0.4,"publicationDate":"2019-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78197538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-02DOI: 10.1080/07315171.2018.1564875
Raghavendra Sagar
Abstract In this paper, we report synthesis, structural, microstructure and electrical study of Mn3O4. Manganese oxide in the form of Mn3O4 was prepared by co-precipitation technique using manganese nitrate as source at the calcination temperature of 400 °C. The crystal structure has been refined by least squire fitting method using powder X-ray diffraction data. The structure refinement showed the formation of single phase with no any secondary phases. The lattice parameter and cell volume has been calculated manually from standard equations and verified by UNITCELL software program. The particle size was also determined from the XRD pattern using Scherrer’s equation. The microstructure of calcined and sintered sample was characterized by scanning electron microscopy. The temperature dependent dc conductivity of the Mn3O4 pellet was studied in the temperature range between room temperature to 500 °C. The conductivity of this spinal was very less at room temperature and increased with increasing temperature exhibiting negative temperature of coefficient of resistance behavior with activation energy 0.91eV.
{"title":"Structural and electrical studies of nanocrystalline Mn3O4","authors":"Raghavendra Sagar","doi":"10.1080/07315171.2018.1564875","DOIUrl":"https://doi.org/10.1080/07315171.2018.1564875","url":null,"abstract":"Abstract In this paper, we report synthesis, structural, microstructure and electrical study of Mn3O4. Manganese oxide in the form of Mn3O4 was prepared by co-precipitation technique using manganese nitrate as source at the calcination temperature of 400 °C. The crystal structure has been refined by least squire fitting method using powder X-ray diffraction data. The structure refinement showed the formation of single phase with no any secondary phases. The lattice parameter and cell volume has been calculated manually from standard equations and verified by UNITCELL software program. The particle size was also determined from the XRD pattern using Scherrer’s equation. The microstructure of calcined and sintered sample was characterized by scanning electron microscopy. The temperature dependent dc conductivity of the Mn3O4 pellet was studied in the temperature range between room temperature to 500 °C. The conductivity of this spinal was very less at room temperature and increased with increasing temperature exhibiting negative temperature of coefficient of resistance behavior with activation energy 0.91eV.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"4 1","pages":"94 - 98"},"PeriodicalIF":0.4,"publicationDate":"2018-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87326700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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