{"title":"反铁磁性、超顺磁性以及 A 阳离子分布对 LaSrFeO4 Ruddlesden-Popper 氧化物磁性能的影响:实验与理论的综合研究","authors":"","doi":"10.1016/j.physb.2024.416550","DOIUrl":null,"url":null,"abstract":"<div><p>Understanding the structure–property relationship in complex magnetic oxides is crucial for developing new magnetic materials. In this study, we synthesized LaSrFeO<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> Ruddlesden–Popper oxide using spray-pyrolysis method. Electron paramagnetic resonance (EPR) spectra revealed two Fe-associated lines: a broad line indicating short-range antiferromagnetic (AFM) order, disappearing at 375 K, and a narrow line due to the presence of superparamagnetic phase. The magnetic moment from the linewidth’s temperature dependence was <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>19</mn></mrow></msup></mrow></math></span> A m<sup>2</sup>. EPR intensity analysis estimated the superparamagnetic to antiferromagnetic phase ratio at 0.014 <span><math><mo>±</mo></math></span> 0.004.</p><p>Using density-functional theory with Agapito–Curtarolo–Buongiorno–Nardelli (ACBN0) pseudo-hybrid functional including self-consistent Hubbard <span><math><mi>U</mi></math></span> correction, we calculated the density of states for two La/Sr atomic distributions. The calculations show that a uniform La/Sr distribution perturbs 2D symmetry of Fe 3<span><math><mi>d</mi></math></span> states, which can contribute to the observed lowering of the critical exponent <span><math><mi>β</mi></math></span> for the magnetically ordered phase. These results highlight the impact of La/Sr distribution on LaSrFeO<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>’s properties.</p></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8000,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Antiferromagnetism, superparamagnetism, and effects of A-cation distribution on magnetic properties of LaSrFeO4 Ruddlesden–Popper oxides: A combined experimental and theoretical study\",\"authors\":\"\",\"doi\":\"10.1016/j.physb.2024.416550\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Understanding the structure–property relationship in complex magnetic oxides is crucial for developing new magnetic materials. In this study, we synthesized LaSrFeO<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> Ruddlesden–Popper oxide using spray-pyrolysis method. Electron paramagnetic resonance (EPR) spectra revealed two Fe-associated lines: a broad line indicating short-range antiferromagnetic (AFM) order, disappearing at 375 K, and a narrow line due to the presence of superparamagnetic phase. The magnetic moment from the linewidth’s temperature dependence was <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>19</mn></mrow></msup></mrow></math></span> A m<sup>2</sup>. EPR intensity analysis estimated the superparamagnetic to antiferromagnetic phase ratio at 0.014 <span><math><mo>±</mo></math></span> 0.004.</p><p>Using density-functional theory with Agapito–Curtarolo–Buongiorno–Nardelli (ACBN0) pseudo-hybrid functional including self-consistent Hubbard <span><math><mi>U</mi></math></span> correction, we calculated the density of states for two La/Sr atomic distributions. The calculations show that a uniform La/Sr distribution perturbs 2D symmetry of Fe 3<span><math><mi>d</mi></math></span> states, which can contribute to the observed lowering of the critical exponent <span><math><mi>β</mi></math></span> for the magnetically ordered phase. These results highlight the impact of La/Sr distribution on LaSrFeO<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>’s properties.</p></div>\",\"PeriodicalId\":20116,\"journal\":{\"name\":\"Physica B-condensed Matter\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.8000,\"publicationDate\":\"2024-09-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Physica B-condensed Matter\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0921452624008913\",\"RegionNum\":3,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"PHYSICS, CONDENSED MATTER\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physica B-condensed Matter","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0921452624008913","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, CONDENSED MATTER","Score":null,"Total":0}
引用次数: 0
摘要
了解复杂磁性氧化物的结构-性能关系对于开发新型磁性材料至关重要。在这项研究中,我们采用喷雾热解方法合成了 LaSrFeO4 Ruddlesden-Popper 氧化物。电子顺磁共振(EPR)光谱显示了两条与铁有关的线:一条宽线表示短程反铁磁性(AFM)有序,在 375 K 时消失;另一条窄线是由于超顺磁性相的存在。从线宽的温度依赖性得出的磁矩为 10-19 A m2。通过使用 Agapito-Curtarolo-Buongiorno-Nardelli (ACBN0) 伪混合函数(包括自洽 Hubbard U 修正)的密度泛函理论,我们计算了两种 La/Sr 原子分布的状态密度。计算结果表明,均匀的 La/Sr 分布会扰乱铁 3d 态的二维对称性,从而导致观察到的磁有序相临界指数 β 下降。这些结果突显了 La/Sr 分布对 LaSrFeO4 性质的影响。
Antiferromagnetism, superparamagnetism, and effects of A-cation distribution on magnetic properties of LaSrFeO4 Ruddlesden–Popper oxides: A combined experimental and theoretical study
Understanding the structure–property relationship in complex magnetic oxides is crucial for developing new magnetic materials. In this study, we synthesized LaSrFeO Ruddlesden–Popper oxide using spray-pyrolysis method. Electron paramagnetic resonance (EPR) spectra revealed two Fe-associated lines: a broad line indicating short-range antiferromagnetic (AFM) order, disappearing at 375 K, and a narrow line due to the presence of superparamagnetic phase. The magnetic moment from the linewidth’s temperature dependence was A m2. EPR intensity analysis estimated the superparamagnetic to antiferromagnetic phase ratio at 0.014 0.004.
Using density-functional theory with Agapito–Curtarolo–Buongiorno–Nardelli (ACBN0) pseudo-hybrid functional including self-consistent Hubbard correction, we calculated the density of states for two La/Sr atomic distributions. The calculations show that a uniform La/Sr distribution perturbs 2D symmetry of Fe 3 states, which can contribute to the observed lowering of the critical exponent for the magnetically ordered phase. These results highlight the impact of La/Sr distribution on LaSrFeO’s properties.
期刊介绍:
Physica B: Condensed Matter comprises all condensed matter and material physics that involve theoretical, computational and experimental work.
Papers should contain further developments and a proper discussion on the physics of experimental or theoretical results in one of the following areas:
-Magnetism
-Materials physics
-Nanostructures and nanomaterials
-Optics and optical materials
-Quantum materials
-Semiconductors
-Strongly correlated systems
-Superconductivity
-Surfaces and interfaces