Herein, the effects of crystalline phase structures of rare earth oxides on active oxygen and basic sites were investigated. The fluorite structure shows the best lattice oxygen mobility and redox properties due to its open structure and weakest Ln-O bond strength. For Pr6O11 and Tb4O7, the presence of polyvalent cation states further enhances these properties. Based on the basicity and number of basic sites, the surfaces of A-type, B-type, and C-type lanthanide sesquioxides facilitate the generation of chemisorbed oxygen species in the following order: A-type > B-type > C-type. Furthermore, the basicity and amount of chemisorbed oxygen species are dependent on the electronegativity of rare earth elements, which decreases gradually from La to Lu. This is because from La2O3 to Lu2O3, electrons are less biased toward oxygen, the basicity of lattice oxygen decreases, and fewer electrons are produced for gaseous oxygen activation and chemisorbed oxygen generation.
本文研究了稀土氧化物晶相结构对活性氧和碱性位点的影响。萤石结构因其开放结构和最弱的 Ln-O 键强度而显示出最佳的晶格氧迁移率和氧化还原特性。对于 Pr6O11 和 Tb4O7，多价阳离子态的存在进一步增强了这些特性。根据碱性和碱性位点的数量，A 型、B 型和 C 型镧系倍半氧化物的表面按以下顺序促进化学吸附氧的生成：A型；B型；C型。此外，化学吸附氧的碱性和数量取决于稀土元素的电负性，从 La 到 Lu，电负性逐渐降低。这是因为从 La2O3 到 Lu2O3，电子对氧的偏向性降低，晶格氧的碱性降低，用于气态氧活化和化学吸附氧生成的电子减少。
{"title":"Influence of crystalline phase structure of rare earth oxides on active oxygen and basic sites","authors":"Jianping Fu , Xuefang Wen , Zhiyong Xu, Yongsheng Guo, Chunshan Ke, Junwei Xu","doi":"10.1016/j.solidstatesciences.2024.107738","DOIUrl":"10.1016/j.solidstatesciences.2024.107738","url":null,"abstract":"<div><div>Herein, the effects of crystalline phase structures of rare earth oxides on active oxygen and basic sites were investigated. The fluorite structure shows the best lattice oxygen mobility and redox properties due to its open structure and weakest Ln-O bond strength. For Pr<sub>6</sub>O<sub>11</sub> and Tb<sub>4</sub>O<sub>7</sub>, the presence of polyvalent cation states further enhances these properties. Based on the basicity and number of basic sites, the surfaces of A-type, B-type, and C-type lanthanide sesquioxides facilitate the generation of chemisorbed oxygen species in the following order: A-type > B-type > C-type. Furthermore, the basicity and amount of chemisorbed oxygen species are dependent on the electronegativity of rare earth elements, which decreases gradually from La to Lu. This is because from La<sub>2</sub>O<sub>3</sub> to Lu<sub>2</sub>O<sub>3</sub>, electrons are less biased toward oxygen, the basicity of lattice oxygen decreases, and fewer electrons are produced for gaseous oxygen activation and chemisorbed oxygen generation.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"158 ","pages":"Article 107738"},"PeriodicalIF":3.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-31DOI: 10.1016/j.solidstatesciences.2024.107737
Nataliya Muts, Yaroslav Tokaychuk, Roman Gladyshevskii
The existence of five new ternary compounds with Gd1.33Pt3Al8-type structure (Pearson symbol hR51, space group R-3m) was established by means of X-ray powder diffraction and energy-dispersive X-ray spectroscopy: Tb1.33Ni3Ga8 (а = 4.2056(1), с = 37.8913(9) Å), Ho1.33Ni3Ga8 (а = 4.19666(9), с = 37.7882(9) Å), Er1.33Ni3Ga8 (a = 4.19290(8), c = 37.7446(8) Å), Tm1.33Ni3Ga8 (a = 4.18819(7), c = 37.6980(7) Å), and Lu1.33Ni3Ga8 (a = 4.1826(1), c = 37.647(1) Å). The structures of the ternary R1.33Ni3Ga8 compounds belong to a family of linear-intergrowth structures with the general formula R0.67TnM2n + m and are built from atom layers of the composition R0.67Ga (R0.67M), separated by single or double NiGa2 slabs (TM2). The layers containing the rare-earth metal atoms are characterized by a disordered distribution of rare-earth metal atoms and Ga-atom triangles.
通过 X 射线粉末衍射和能量色散 X 射线光谱，确定了五种具有 Gd1.33Pt3Al8 型结构（皮尔逊符号 hR51，空间群 R-3m）的新三元化合物的存在：Tb1.33Ni3Ga8（а = 4.2056(1)，с = 37.8913(9)埃），Ho1.33Ni3Ga8（а = 4.19666(9)，с = 37.7882(9)埃），Er1.33Ni3Ga8（a = 4.19290(8), c = 37.7446(8) Å)、Tm1.33Ni3Ga8 (a = 4.18819(7), c = 37.6980(7) Å)和 Lu1.33Ni3Ga8 (a = 4.1826(1), c = 37.647(1) Å)。R1.33Ni3Ga8 三元化合物的结构属于线性互生结构系列，通式为 R0.67TnM2n + m，由 R0.67Ga (R0.67M)原子层构成，原子层之间由单层或双层 NiGa2 板（TM2）隔开。含有稀土金属原子的原子层的特点是稀土金属原子和镓原子三角形的无序分布。
{"title":"Crystal structures of the R1.33Ni3Ga8 (R = Tb, Ho, Er, Tm, Lu) compounds","authors":"Nataliya Muts, Yaroslav Tokaychuk, Roman Gladyshevskii","doi":"10.1016/j.solidstatesciences.2024.107737","DOIUrl":"10.1016/j.solidstatesciences.2024.107737","url":null,"abstract":"<div><div>The existence of five new ternary compounds with Gd<sub>1.33</sub>Pt<sub>3</sub>Al<sub>8</sub>-type structure (Pearson symbol <em>hR</em>51, space group <em>R-</em>3<em>m</em>) was established by means of X-ray powder diffraction and energy-dispersive X-ray spectroscopy: Tb<sub>1.33</sub>Ni<sub>3</sub>Ga<sub>8</sub> (<em>а</em> = 4.2056(1), <em>с</em> = 37.8913(9) Å), Ho<sub>1.33</sub>Ni<sub>3</sub>Ga<sub>8</sub> (<em>а</em> = 4.19666(9), <em>с</em> = 37.7882(9) Å), Er<sub>1.33</sub>Ni<sub>3</sub>Ga<sub>8</sub> (<em>a =</em> 4.19290(8), <em>c =</em> 37.7446(8) Å), Tm<sub>1.33</sub>Ni<sub>3</sub>Ga<sub>8</sub> (<em>a =</em> 4.18819(7), <em>c =</em> 37.6980(7) Å), and Lu<sub>1.33</sub>Ni<sub>3</sub>Ga<sub>8</sub> (<em>a =</em> 4.1826(1), <em>c =</em> 37.647(1) Å). The structures of the ternary <em>R</em><sub>1.33</sub>Ni<sub>3</sub>Ga<sub>8</sub> compounds belong to a family of linear-intergrowth structures with the general formula <em>R</em><sub>0.67</sub><em>T</em><sub><em>n</em></sub><em>M</em><sub>2<em>n</em> + <em>m</em></sub> and are built from atom layers of the composition <em>R</em><sub>0.67</sub>Ga (<em>R</em><sub>0.67</sub><em>M</em>), separated by single or double NiGa<sub>2</sub> slabs (<em>TM</em><sub>2</sub>). The layers containing the rare-earth metal atoms are characterized by a disordered distribution of rare-earth metal atoms and Ga-atom triangles.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"158 ","pages":"Article 107737"},"PeriodicalIF":3.4,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
RAlB4 (R = rare earth element) has attracted increasing attention due to recent reports on its properties in magnetic, thermoelectric and superconducting materials. The authors developed and we investigated the formation of the solid solution Yb(Al0.995T0.005)B4 (T = Cr, Mn or Fe) compounds in which the Al position of YbAlB4 is substituted with T atoms using the Al flux method. In this study, crystals of the boride Yb(Al0.995T0.005)B4 (T = Mo or W) were grown by using Al flux mixed with T metal at 1773 K for 5h. Yb(Al0.995W0.005)B4 was obtained as the single phase, however, in the case of Yb(Al0.995Mo0.005)B4, a small amount of AlMoB crystals was contained. The crystals were measured using a micro-Vickers hardness tester, and the oxidation resistance was examined in air using DTA-TG apparatus. Comparing the lattice constants and chemical composition of YbAlB4 and Yb(Al0.995T0.005)B4, it were understood that the lattice constant of Yb(Al,T)B4 were larger than that of YbAlB4 crystals. Yb(Al,T)B4 were grown as a solid solution contained about 40 % of each T metal. The hardness values were 11.0(±0.7) GPa for Yb(Al0.995Mo0.005)B4 and 15.7(±1.9) GPa for Yb(Al0.995W0.005)B4. The oxidation of Yb(Al,T)B4 starts in the range of 971–987 K. The oxidation onset temperature during the heating of Yb(Al,T)B4 is about 100 K higher than YbAlB4.
由于最近有关 RAlB4（R = 稀土元素）在磁性、热电和超导材料中特性的报道，它引起了越来越多的关注。作者开发并研究了固溶体 Yb(Al0.995T0.005)B4（T = Cr、Mn 或 Fe）化合物的形成，其中 YbAlB4 的 Al 位置使用 Al flux 方法被 T 原子取代。在这项研究中，通过在 1773 K 下使用混合有 T 金属的铝助熔剂 5 小时，生长出了硼化物 Yb(Al0.995T0.005)B4 （T = Mo 或 W）的晶体。得到的 Yb(Al0.995W0.005)B4 为单相，但在 Yb(Al0.995Mo0.005)B4 中，含有少量 AlMoB 晶体。使用显微维氏硬度计测量了晶体的硬度，并使用 DTA-TG 仪器检测了晶体在空气中的抗氧化性。通过比较 YbAlB4 和 Yb（Al0.995T0.005）B4 的晶格常数和化学成分可知，Yb（Al,T）B4 的晶格常数大于 YbAlB4 晶体的晶格常数。Yb(Al,T)B4以固溶体的形式生长，每种 T 金属的含量约为 40%。Yb(Al0.995Mo0.005)B4 的硬度值为 11.0(±0.7) GPa，Yb(Al0.995W0.005)B4 的硬度值为 15.7(±1.9) GPa。Yb(Al,T)B4 的氧化开始于 971-987 K 之间。
{"title":"Syntheses and some properties of solid solution Yb(Al,T)B4 (T = Mo or W) compounds","authors":"Kaoru Kouzu , Shigeru Okada , Takeshi Hagiwara , Akiko Nomura , Kunio Yubuta , Takao Mori , Toetsu Shishido , Akira Yoshikawa","doi":"10.1016/j.solidstatesciences.2024.107735","DOIUrl":"10.1016/j.solidstatesciences.2024.107735","url":null,"abstract":"<div><div><em>R</em>AlB<sub>4</sub> (<em>R</em> = rare earth element) has attracted increasing attention due to recent reports on its properties in magnetic, thermoelectric and superconducting materials. The authors developed and we investigated the formation of the solid solution Yb(Al<sub>0.995</sub><em>T</em><sub>0.005</sub>)B<sub>4</sub> (<em>T</em> = Cr, Mn or Fe) compounds in which the Al position of YbAlB<sub>4</sub> is substituted with <em>T</em> atoms using the Al flux method. In this study, crystals of the boride Yb(Al<sub>0.995</sub><em>T</em><sub>0.005</sub>)B<sub>4</sub> (<em>T</em> = Mo or W) were grown by using Al flux mixed with <em>T</em> metal at 1773 K for 5h. Yb(Al<sub>0.995</sub>W<sub>0.005</sub>)B<sub>4</sub> was obtained as the single phase, however, in the case of Yb(Al<sub>0.995</sub>Mo<sub>0.005</sub>)B<sub>4</sub>, a small amount of AlMoB crystals was contained. The crystals were measured using a micro-Vickers hardness tester, and the oxidation resistance was examined in air using DTA-TG apparatus. Comparing the lattice constants and chemical composition of YbAlB<sub>4</sub> and Yb(Al<sub>0.995</sub><em>T</em><sub>0.005</sub>)B<sub>4</sub>, it were understood that the lattice constant of Yb(Al,<em>T</em>)B<sub>4</sub> were larger than that of YbAlB<sub>4</sub> crystals. Yb(Al,<em>T</em>)B<sub>4</sub> were grown as a solid solution contained about 40 % of each <em>T</em> metal. The hardness values were 11.0(±0.7) GPa for Yb(Al<sub>0.995</sub>Mo<sub>0.005</sub>)B<sub>4</sub> and 15.7(±1.9) GPa for Yb(Al<sub>0.995</sub>W<sub>0.005</sub>)B<sub>4</sub>. The oxidation of Yb(Al,<em>T</em>)B<sub>4</sub> starts in the range of 971–987 K. The oxidation onset temperature during the heating of Yb(Al,<em>T</em>)B<sub>4</sub> is about 100 K higher than YbAlB<sub>4</sub>.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"158 ","pages":"Article 107735"},"PeriodicalIF":3.4,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-30DOI: 10.1016/j.solidstatesciences.2024.107736
Karolina Podgórska , Damian Rybicki , Lan Maria Tran , Wojciech Tabiś , Łukasz Gondek , Michał Babij
Europium-based materials are highly attractive due to their diverse range of physical properties. In these studies, we aimed to synthesize single crystals of the potentially topological semimetallic compound EuAgP, which up to this day has only been obtained in polycrystalline form. The flux method was employed for the syntheses, using fluxes such as: Bi, Sn, Pb, and In, in their various ratios. The purpose of using Bi flux was to try synthesizing an analog of EuAgAs single crystals, by fully substituting arsenic with phosphorus. The obtained crystals were characterized by x-ray diffraction and scanning electron microscopy. Despite many unsuccessful attempts to synthesize EuAgP single crystals, the study provides valuable insights into how different fluxes and their ratios influence the final synthesis product. It also underscores the complexity of designing analogs between arsenides and phosphides.
铕基材料因其多种多样的物理特性而极具吸引力。在这些研究中，我们的目标是合成潜在拓扑半金属化合物 EuAgP 的单晶体。合成过程中采用了助熔剂法，使用的助熔剂包括：Bi、Sn、Pb 和 EuAgP：Bi、Sn、Pb 和 In 等不同比例的助熔剂。使用铋助熔剂的目的是尝试用磷完全取代砷，合成类似于 EuAgAs 的单晶体。获得的晶体通过 X 射线衍射和扫描电子显微镜进行了表征。尽管合成 EuAgP 单晶体的尝试多次失败，但这项研究提供了关于不同通量及其比例如何影响最终合成产物的宝贵见解。它还强调了设计砷化物和磷化物之间类似物的复杂性。
{"title":"Synthesis of europium-based crystals containing As or P by a flux method: Attempts to grow EuAgP single crystals","authors":"Karolina Podgórska , Damian Rybicki , Lan Maria Tran , Wojciech Tabiś , Łukasz Gondek , Michał Babij","doi":"10.1016/j.solidstatesciences.2024.107736","DOIUrl":"10.1016/j.solidstatesciences.2024.107736","url":null,"abstract":"<div><div>Europium-based materials are highly attractive due to their diverse range of physical properties. In these studies, we aimed to synthesize single crystals of the potentially topological semimetallic compound EuAgP, which up to this day has only been obtained in polycrystalline form. The flux method was employed for the syntheses, using fluxes such as: Bi, Sn, Pb, and In, in their various ratios. The purpose of using Bi flux was to try synthesizing an analog of EuAgAs single crystals, by fully substituting arsenic with phosphorus. The obtained crystals were characterized by x-ray diffraction and scanning electron microscopy. Despite many unsuccessful attempts to synthesize EuAgP single crystals, the study provides valuable insights into how different fluxes and their ratios influence the final synthesis product. It also underscores the complexity of designing analogs between arsenides and phosphides.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"158 ","pages":"Article 107736"},"PeriodicalIF":3.4,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-30DOI: 10.1016/j.solidstatesciences.2024.107734
Zhihao Wang , Huiwei Ding , Qiaofeng Han
For the first time, pure Bi3O4Br with a uniform square sheet-like structure was synthesized using a hydrothermal method at 180 °C and pH of 12.5 by employing bismuth citrate as the bismuth source without any surfactant. The photocatalytic activity of Bi3O4Br for the degradation of methylene blue (MB), tetracycline (TC), methyl violet (MV), and rhodamine B (RhB) was evaluated under visible light illumination and the results showed that the as-prepared Bi3O4Br exhibited excellent photodegradation efficiency for MB with an apparent rate constant (ka) of 0.02676 min−1, superior to TC, MV and RhB with ka = 0.00899 min−1, 0.00073 min−1 and 0.00409 min−1, respectively. Since the direct oxidation of the holes predominates in the degradation process, the study on the photocatalytic mechanism suggested that a more positive valence band (VB) potential of Bi3O4Br than HOMO orbital position of MB was prerequisite and also, the smaller the difference between VB potential of a photocatalyst and HOMO energy level of a pollutant, the faster the migration of the holes and subsequent oxidation of pollutant.
{"title":"Unexpectedly high degradation efficiency for MB on Bi3O4Br photocatalyst obtained from bismuth citrate","authors":"Zhihao Wang , Huiwei Ding , Qiaofeng Han","doi":"10.1016/j.solidstatesciences.2024.107734","DOIUrl":"10.1016/j.solidstatesciences.2024.107734","url":null,"abstract":"<div><div>For the first time, pure Bi<sub>3</sub>O<sub>4</sub>Br with a uniform square sheet-like structure was synthesized using a hydrothermal method at 180 °C and pH of 12.5 by employing bismuth citrate as the bismuth source without any surfactant. The photocatalytic activity of Bi<sub>3</sub>O<sub>4</sub>Br for the degradation of methylene blue (MB), tetracycline (TC), methyl violet (MV), and rhodamine B (RhB) was evaluated under visible light illumination and the results showed that the as-prepared Bi<sub>3</sub>O<sub>4</sub>Br exhibited excellent photodegradation efficiency for MB with an apparent rate constant (<em>k</em><sub>a</sub>) of 0.02676 min<sup>−1</sup>, superior to TC, MV and RhB with <em>k</em><sub>a</sub> = 0.00899 min<sup>−1</sup>, 0.00073 min<sup>−1</sup> and 0.00409 min<sup>−1</sup>, respectively. Since the direct oxidation of the holes predominates in the degradation process, the study on the photocatalytic mechanism suggested that a more positive valence band (VB) potential of Bi<sub>3</sub>O<sub>4</sub>Br than HOMO orbital position of MB was prerequisite and also, the smaller the difference between VB potential of a photocatalyst and HOMO energy level of a pollutant, the faster the migration of the holes and subsequent oxidation of pollutant.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"158 ","pages":"Article 107734"},"PeriodicalIF":3.4,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-29DOI: 10.1016/j.solidstatesciences.2024.107727
I. Turek
Intrinsic spin currents are encountered in noncentrosymmetric crystals without any external electric fields; these currents are caused by spin–orbit interaction. In this paper, various theoretical aspects of this phenomenon in bulk ferromagnets are studied by using group theory, perturbation expansion, and calculations for model and real systems. The group-theoretical analysis of the spin-current tensor shows that the absence of space-inversion symmetry is not a sufficient condition for appearance of the intrinsic spin currents. The perturbation expansion proves that in the regime of exchange splitting dominating over spin–orbit interaction, the spin polarization of the intrinsic currents is nearly perpendicular to the direction of magnetization. First-principles calculations are carried out for NiMnSb and CoMnFeSi ferromagnetic compounds, both featured by a tetrahedral crystallographic point group. The dependence of the spin-current tensor on the direction of magnetization is approximated by a simple quadratic formula containing two constants; the relative error of this approximation is found as small as a few percent for both compounds.
{"title":"Intrinsic spin currents in bulk noncentrosymmetric ferromagnets","authors":"I. Turek","doi":"10.1016/j.solidstatesciences.2024.107727","DOIUrl":"10.1016/j.solidstatesciences.2024.107727","url":null,"abstract":"<div><div>Intrinsic spin currents are encountered in noncentrosymmetric crystals without any external electric fields; these currents are caused by spin–orbit interaction. In this paper, various theoretical aspects of this phenomenon in bulk ferromagnets are studied by using group theory, perturbation expansion, and calculations for model and real systems. The group-theoretical analysis of the spin-current tensor shows that the absence of space-inversion symmetry is not a sufficient condition for appearance of the intrinsic spin currents. The perturbation expansion proves that in the regime of exchange splitting dominating over spin–orbit interaction, the spin polarization of the intrinsic currents is nearly perpendicular to the direction of magnetization. First-principles calculations are carried out for NiMnSb and CoMnFeSi ferromagnetic compounds, both featured by a tetrahedral crystallographic point group. The dependence of the spin-current tensor on the direction of magnetization is approximated by a simple quadratic formula containing two constants; the relative error of this approximation is found as small as a few percent for both compounds.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"158 ","pages":"Article 107727"},"PeriodicalIF":3.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Low-temperature phase manganese bismuth (LTP-MnBi) and a series of aluminum (Al) composites were synthesized using a potentially facile and scalable low-temperature liquid-phase sintering method in a vacuum at 300 °C. The incorporation of up to 10 at% Al led to a significant enhancement in coercivity (Hc), increasing from 2.32 ± 0.04 to 4.15 ± 0.07 kOe, while saturation magnetization showed a slight decrease of less than 3 %. However, beyond this concentration, a dramatic reduction in Hc was observed. The density of the freshly compacted powders, which included up to 10 at% Al, remained relatively constant at 7.47–7.58 g/cm³ but decreased with excess Al. A maximum energy product (BH)max of 1 MGOe was achieved in the fresh sample, with a 16 % enhancement in (BH)max in the MnBi composite containing 5 at% Al. Scanning electron microscopy revealed distinct MnBi and Bi-rich regions, while Al-rich areas became prominent at Al concentrations above 10 at%. Energy dispersive spectroscopy confirmed that only 3–5 at% Al could be effectively incorporated into Mn-Bi regions, with excess Al unevenly distributed on the surface. X-ray photoelectron spectroscopy indicated the formation of Al, Al₂O₃, and potential Mn-Bi-Al ternary alloys. Additionally, slab-DFT models, such as AlMn/MnBi, indicate that Al inclusion enhances the magnetization in MnBi composites, providing insights into its effects on the magnetic properties of Mn-Bi systems. These findings offer promising strategies to address the challenges posed by excess Bi in the MnBi structure, potentially optimizing the magnetic performance of similar non-magnetic or soft-magnetic composite systems.
{"title":"Formation and characterization of Mn-Bi-Al ternary alloys of enhanced magnetic performance in MnBi/Al composites","authors":"Thanit Saisopa , Wutthigrai Sailuam , Puttamawan Juntree , Hideki Nakajima , Ratchadaporn Supruangnet , Denis Céolin , Supree Pinitsoontorn , Chitnarong Sirisathitkul , Prayoon Songsiriritthigul , Narasak Pandech , Tanachat Eknapakul","doi":"10.1016/j.solidstatesciences.2024.107730","DOIUrl":"10.1016/j.solidstatesciences.2024.107730","url":null,"abstract":"<div><div>Low-temperature phase manganese bismuth (LTP-MnBi) and a series of aluminum (Al) composites were synthesized using a potentially facile and scalable low-temperature liquid-phase sintering method in a vacuum at 300 °C. The incorporation of up to 10 at% Al led to a significant enhancement in coercivity (H<sub>c</sub>), increasing from 2.32 ± 0.04 to 4.15 ± 0.07 kOe, while saturation magnetization showed a slight decrease of less than 3 %. However, beyond this concentration, a dramatic reduction in H<sub>c</sub> was observed. The density of the freshly compacted powders, which included up to 10 at% Al, remained relatively constant at 7.47–7.58 g/cm³ but decreased with excess Al. A maximum energy product (BH)<sub>max</sub> of 1 MGOe was achieved in the fresh sample, with a 16 % enhancement in (BH)<sub>max</sub> in the MnBi composite containing 5 at% Al. Scanning electron microscopy revealed distinct MnBi and Bi-rich regions, while Al-rich areas became prominent at Al concentrations above 10 at%. Energy dispersive spectroscopy confirmed that only 3–5 at% Al could be effectively incorporated into Mn-Bi regions, with excess Al unevenly distributed on the surface. X-ray photoelectron spectroscopy indicated the formation of Al, Al₂O₃, and potential Mn-Bi-Al ternary alloys. Additionally, slab-DFT models, such as AlMn/MnBi, indicate that Al inclusion enhances the magnetization in MnBi composites, providing insights into its effects on the magnetic properties of Mn-Bi systems. These findings offer promising strategies to address the challenges posed by excess Bi in the MnBi structure, potentially optimizing the magnetic performance of similar non-magnetic or soft-magnetic composite systems.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"157 ","pages":"Article 107730"},"PeriodicalIF":3.4,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-23DOI: 10.1016/j.solidstatesciences.2024.107732
Hai-Feng Nie , Ying-Hua Liang , Jihoon Park , Tian-Hong Zhou , Bao-Chao Zhang , Ping-Zhan Si , Xing Zheng , Youngwoon Song , Chul-Jin Choi , Qiong Wu
The magnetic properties of Sm6Mn23-based alloys are still not fully understood for their high complexity in magnetic and crystallographic structures. This work presents studies of the structure and magnetic properties of Sm6Mn23 and Sm5LaMn23 alloys. The results show that both the binary and La-substituted ternary alloys crystallize in a cubic Th6Mn23 type structure (Fm-3m) with trace amount of Mn impurities. The lattice parameter of Sm5LaMn23 is slightly larger than that of Sm6Mn23. The Curie temperature of Sm5LaMn23 is ∼403 K, which is lower than that of Sm6Mn23. A field-dependent magnetic transition was observed in Sm5LaMn23, which shows a decreasing temperature at which Sm5LaMn23 exhibiting maximal magnetization with increasing field, indicating a suppression of the antiferromagnetic coupling of the rare earth and Mn moments under applied field. Large coercivities up to 0.74 T and 1.2 T are observed in Sm5LaMn23 bulk alloys and powders, respectively. The saturate magnetization, the remanent magnetization, and the coercivity of Sm5LaMn23 at 5 K are much higher than that of Sm6Mn23. The ball-milled Sm5LaMn23 powders exhibit significantly enhanced coercivity and magnetization. The refinement of the grain size during ball-milling results in the enhanced coercivity. The magnetic purification of the powders and possible local ferromagnetic configuration of the surface Mn atoms may result in the enhanced magnetization.
由于 Sm6Mn23 基合金在磁性和晶体结构上的高度复杂性，其磁性能仍未得到充分了解。本研究对 Sm6Mn23 和 Sm5LaMn23 合金的结构和磁性能进行了研究。结果表明，二元合金和 La 取代的三元合金都结晶为立方 Th6Mn23 型结构 (Fm-3m)，其中含有微量的锰杂质。Sm5LaMn23 的晶格参数略大于 Sm6Mn23。Sm5LaMn23 的居里温度为 403 K，低于 Sm6Mn23。在 Sm5LaMn23 中观察到了与磁场相关的磁转变，即随着磁场的增加，Sm5LaMn23 表现出最大磁化时的温度降低，这表明在外加磁场下稀土和锰矩的反铁磁耦合受到了抑制。在 Sm5LaMn23 块体合金和粉末中分别观察到高达 0.74 T 和 1.2 T 的大矫顽力。在 5 K 时，Sm5LaMn23 的饱和磁化、剩磁和矫顽力远高于 Sm6Mn23。球磨 Sm5LaMn23 粉末的矫顽力和磁化率明显提高。球磨过程中晶粒尺寸的细化导致了矫顽力的增强。粉末的磁性纯化和表面锰原子可能存在的局部铁磁性构型可能会导致磁化增强。
{"title":"Large coercivity and enhanced magnetization in La-substituted Sm6Mn23 alloys","authors":"Hai-Feng Nie , Ying-Hua Liang , Jihoon Park , Tian-Hong Zhou , Bao-Chao Zhang , Ping-Zhan Si , Xing Zheng , Youngwoon Song , Chul-Jin Choi , Qiong Wu","doi":"10.1016/j.solidstatesciences.2024.107732","DOIUrl":"10.1016/j.solidstatesciences.2024.107732","url":null,"abstract":"<div><div>The magnetic properties of Sm<sub>6</sub>Mn<sub>23</sub>-based alloys are still not fully understood for their high complexity in magnetic and crystallographic structures. This work presents studies of the structure and magnetic properties of Sm<sub>6</sub>Mn<sub>23</sub> and Sm<sub>5</sub>LaMn<sub>23</sub> alloys. The results show that both the binary and La-substituted ternary alloys crystallize in a cubic Th<sub>6</sub>Mn<sub>23</sub> type structure (Fm-3m) with trace amount of Mn impurities. The lattice parameter of Sm<sub>5</sub>LaMn<sub>23</sub> is slightly larger than that of Sm<sub>6</sub>Mn<sub>23</sub>. The Curie temperature of Sm<sub>5</sub>LaMn<sub>23</sub> is ∼403 K, which is lower than that of Sm<sub>6</sub>Mn<sub>23</sub>. A field-dependent magnetic transition was observed in Sm<sub>5</sub>LaMn<sub>23</sub>, which shows a decreasing temperature at which Sm<sub>5</sub>LaMn<sub>23</sub> exhibiting maximal magnetization with increasing field, indicating a suppression of the antiferromagnetic coupling of the rare earth and Mn moments under applied field. Large coercivities up to 0.74 T and 1.2 T are observed in Sm<sub>5</sub>LaMn<sub>23</sub> bulk alloys and powders, respectively. The saturate magnetization, the remanent magnetization, and the coercivity of Sm<sub>5</sub>LaMn<sub>23</sub> at 5 K are much higher than that of Sm<sub>6</sub>Mn<sub>23</sub>. The ball-milled Sm<sub>5</sub>LaMn<sub>23</sub> powders exhibit significantly enhanced coercivity and magnetization. The refinement of the grain size during ball-milling results in the enhanced coercivity. The magnetic purification of the powders and possible local ferromagnetic configuration of the surface Mn atoms may result in the enhanced magnetization.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"157 ","pages":"Article 107732"},"PeriodicalIF":3.4,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We have investigated the solid solution range of single phase La1-xRxRh3B (R = Gd, Lu and Sc) compounds with a cubic anti-perovskite type structure. The behaviors of lattice parameters, hardness, and thermogravimetry–differential thermal analysis (TG-DTA) were also investigated. The cubic anti-perovskite phase exists over the entire composition range x from 0.0 to 1.0 for all La-Gd, La-Lu and La-Sc systems. Both the lattice parameters and the hardness in all La-Gd, La-Lu and La-Sc systems show a linear dependence on the degree of the substitution x of La atom. The results of TG-DTA measurements indicate that oxidation of the compounds in air begins at about 500–600 K. The mixed phases of RBO3, R2O3 and Rh are identified as oxidized products around x = 0.4 to 0.6 composition. The oxidation onset temperature, and weight gains due to the oxidation depend on the degree of substitution x. The behavior of crystallographic and physical/chemical properties in the present compounds La1-xRxRh3B strongly depend on the atomic size of the rare-earth atoms that form the cubic framework.
我们研究了具有立方反超晶型结构的单相 La1-xRxRh3B（R = Gd、Lu 和 Sc）化合物的固溶体范围。同时还研究了晶格参数、硬度和热重-差热分析（TG-DTA）的行为。在所有 La-Gd、La-Lu 和 La-Sc 系统中，立方反超晶相存在于 0.0 至 1.0 的整个成分范围 x 中。所有 La-Gd、La-Lu 和 La-Sc 系统的晶格参数和硬度都与 La 原子的替代程度 x 呈线性关系。TG-DTA 测量结果表明，这些化合物在空气中的氧化始于约 500-600 K。本化合物 La1-xRxRh3B 的晶体学行为和物理/化学特性在很大程度上取决于构成立方框架的稀土原子的原子尺寸。
{"title":"Phase stability of solid solution La1-xRxRh3B (R = Gd, Lu and Sc) compounds with cubic anti-perovskite type structure","authors":"Kunio Yubuta , Akiko Nomura , Kaoru Kouzu , Takao Mori , Shigeru Okada , Toetsu Shishido","doi":"10.1016/j.solidstatesciences.2024.107731","DOIUrl":"10.1016/j.solidstatesciences.2024.107731","url":null,"abstract":"<div><div>We have investigated the solid solution range of single phase La<sub>1-<em>x</em></sub><em>R</em><sub><em>x</em></sub>Rh<sub>3</sub>B (<em>R</em> = Gd, Lu and Sc) compounds with a cubic anti-perovskite type structure. The behaviors of lattice parameters, hardness, and thermogravimetry–differential thermal analysis (TG-DTA) were also investigated. The cubic anti-perovskite phase exists over the entire composition range <em>x</em> from 0.0 to 1.0 for all La-Gd, La-Lu and La-Sc systems. Both the lattice parameters and the hardness in all La-Gd, La-Lu and La-Sc systems show a linear dependence on the degree of the substitution <em>x</em> of La atom. The results of TG-DTA measurements indicate that oxidation of the compounds in air begins at about 500–600 K. The mixed phases of <em>R</em>BO<sub>3</sub>, <em>R</em><sub>2</sub>O<sub>3</sub> and Rh are identified as oxidized products around <em>x</em> = 0.4 to 0.6 composition. The oxidation onset temperature, and weight gains due to the oxidation depend on the degree of substitution <em>x</em>. The behavior of crystallographic and physical/chemical properties in the present compounds La<sub>1-<em>x</em></sub><em>R</em><sub><em>x</em></sub>Rh<sub>3</sub>B strongly depend on the atomic size of the rare-earth atoms that form the cubic framework.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"158 ","pages":"Article 107731"},"PeriodicalIF":3.4,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-23DOI: 10.1016/j.solidstatesciences.2024.107729
Abhigyan Ojha, Sivaiah Bathula
Thermoelectric (TE) materials-based devices are valuable for translating heat into electricity, but the cost is largely driven by the use of purified metals required for efficient TE performance. This study focuses on tetrahedrite materials, which are cost-effective due to their abundance in copper ore mining waste and status as one of the most widespread sulfosalts on Earth. The research investigates the effects of co-doping and iso-valent doping on the TE properties of p-type tetrahedrite samples, specifically Cu10Mn2Sb4S11Se2 (Sample A) and Cu10MnZnSb₄S11Se2 (Sample B). These samples were synthesized using hot pressing at 773 K and compared with the existing pristine compound (Cu10Mn2Sb4S13). Doping with Mn and Zn (1:1) at the Cu site was found to optimize carrier concentration and enhance phonon scattering, leading to an improved power factor. Additionally, the Se substitution at the S site also introduced band degeneracy, further increasing the power factor. Further, sample B exhibited the highest Seebeck coefficient (∼300 μV/K) at 650 K, in comparison to Sample A (∼225 μV/K) and the pristine compound (∼250 μV/K). On the other hand, Sample A demonstrated significantly higher electrical conductivity (∼0.76 × 10⁴ S/m at 650 K), ∿ three times greater than that of the other prepared samples. Notably, the power factor of Sample A (∼0.389 mW/mK2 at 650 K) was more than twice that of Sample B (∼0.141 mW/mK2) and the pristine compound (∼0.160 mW/mK2). These findings suggest that dual-site substitution at the Cu and S positions presents a promising strategy to augment the TE performance of tetrahedrite compounds.
基于热电（TE）材料的设备在将热能转化为电能方面具有重要价值，但其成本在很大程度上取决于使用高效热电性能所需的纯化金属。本研究的重点是四面体材料，由于其大量存在于铜矿废料中，并且是地球上最常见的硫化物之一，因此成本效益很高。研究调查了共掺杂和同价掺杂对 p 型四面体样品 TE 性能的影响，特别是 Cu10Mn2Sb4S11Se2（样品 A）和 Cu10MnZnSb₄S11Se2（样品 B）。这些样品是在 773 K 下通过热压合成的，并与现有的原始化合物（Cu10Mn2Sb4S13）进行了比较。研究发现，在 Cu 位点掺入 Mn 和 Zn（1:1）可优化载流子浓度并增强声子散射，从而提高功率因数。此外，在 S 位点硒的替代也引入了带变性，进一步提高了功率因数。此外，与样品 A（∼225 μV/K）和原始化合物（∼250 μV/K）相比，样品 B 在 650 K 时显示出最高的塞贝克系数（∼300 μV/K）。另一方面，样品 A 的导电率明显更高（650 K 时为 0.76 × 10⁴ S/m），是其他制备样品的三倍。值得注意的是，样品 A 的功率因数（650 K 时为 0.389 mW/mK2）是样品 B（0.141 mW/mK2）和原始化合物（0.160 mW/mK2）的两倍多。这些研究结果表明，在 Cu 和 S 位置进行双位取代是提高四面体化合物 TE 性能的一种可行策略。
{"title":"Achieving enhanced power factor using dual substitution at Cu and S sites in tetrahedrites thermoelectric materials Cu12Sb4S13","authors":"Abhigyan Ojha, Sivaiah Bathula","doi":"10.1016/j.solidstatesciences.2024.107729","DOIUrl":"10.1016/j.solidstatesciences.2024.107729","url":null,"abstract":"<div><div>Thermoelectric (TE) materials-based devices are valuable for translating heat into electricity, but the cost is largely driven by the use of purified metals required for efficient TE performance. This study focuses on tetrahedrite materials, which are cost-effective due to their abundance in copper ore mining waste and status as one of the most widespread sulfosalts on Earth. The research investigates the effects of co-doping and iso-valent doping on the TE properties of p-type tetrahedrite samples, specifically Cu<sub>10</sub>Mn<sub>2</sub>Sb<sub>4</sub>S<sub>11</sub>Se<sub>2</sub> (Sample A) and Cu<sub>10</sub>MnZnSb₄S<sub>11</sub>Se<sub>2</sub> (Sample B). These samples were synthesized using hot pressing at 773 K and compared with the existing pristine compound (Cu<sub>10</sub>Mn<sub>2</sub>Sb<sub>4</sub>S<sub>13</sub>). Doping with Mn and Zn (1:1) at the Cu site was found to optimize carrier concentration and enhance phonon scattering, leading to an improved power factor. Additionally, the Se substitution at the S site also introduced band degeneracy, further increasing the power factor. Further, sample B exhibited the highest Seebeck coefficient (∼300 μV/K) at 650 K, in comparison to Sample A (∼225 μV/K) and the pristine compound (∼250 μV/K). On the other hand, Sample A demonstrated significantly higher electrical conductivity (∼0.76 × 10⁴ S/m at 650 K), ∿ three times greater than that of the other prepared samples. Notably, the power factor of Sample A (∼0.389 mW/mK<sup>2</sup> at 650 K) was more than twice that of Sample B (∼0.141 mW/mK<sup>2</sup>) and the pristine compound (∼0.160 mW/mK<sup>2</sup>). These findings suggest that dual-site substitution at the Cu and S positions presents a promising strategy to augment the TE performance of tetrahedrite compounds.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"157 ","pages":"Article 107729"},"PeriodicalIF":3.4,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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