电荷排序分解动力学和铁磁共振研究B点Cu稀释Pr1‒Sr3MnO的研究
A Bordoloi1, S K Jena1, P Tiwari1
1Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
概括
在Pr0.45Sr0.55MnO3中Jahn-Teller活性Cu的替代破坏了电荷排序 (CO),增强了铁磁秩序和磁晶异性. 这项研究揭示了关键的磁过渡及其与阴离子分布和电子状态的相关性.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 磁力学 磁力学 是一种
背景情况:
- Pr0.45Sr0.55MnO3 (S55) 呈现复杂的磁相,包括铁磁和电荷排序的反铁磁状态,受双交换和电荷排序 (CO) 相互作用的影响.
- 这些相互作用之间的相互作用导致特定温度范围内的混合磁相.
- 了解替代对这些微妙的磁性结构的影响对于材料设计至关重要.
研究的目的:
- 为了研究Jahn-Teller活性Cu替代对Pr0.45Sr0.55MnO3 (S55) 的电荷排序 (CO) 特性的影响.
- 分析磁相图,磁过渡和磁晶异构的结果变化.
- 建立阴离子分布,电子状态和磁性特性之间的相关性.
主要方法:
- 磁化研究以确定磁相图和过渡温度 (TC,TN,TCO).
- 特定热量测量 (CP(T)) 以验证CO过渡温度.
- 铁磁共振 (FMR) 研究以评估磁晶异性和吉尔伯特阻尼因子 (αG).
- 对磁热容量 (CMag) 的临界分析,以确定临界指数.
- 对阴离子分布和电子状态 (Mn3+/4+) 的分析.
主要成果:
- 稀释Cu的替代破坏了S55中的CO状态,导致增强的铁磁秩序,过渡温度更高 (TFN∼273 K) 和显著的磁晶异性.
- 与原始的S55相比,Cu的替代产生了明显的阴离子分布,影响了磁体结构.
- 在S55中观察到与CO现象相关的不可逆转的超磁性过渡 (HT-Max∼8.85kOe在180K),表明TCO的第一阶段过渡.
- 临界指数分析得出α=0.097 (T>TN) 和α=0.154 (T
- FMR参数 (ΔHRes(T),HPP(T),αG(T)) 显示了磁过渡的异常,突出了Mn3+/4+电子状态的作用.
- 在FMR吉尔伯特阻尼 (αG(T)) 和可切换磁变化 (ΔSMax∼-8/+3 J kg-1K-1) 之间建立了强烈的相关性.
结论:
- 雅恩-泰勒活性替代有效地改变了Pr0.45Sr0.55MnO3的磁性和电子性质.
- 这项研究提供了关于电荷排序,磁相互作用和矿结构修改的复杂相互作用的见解.
- 观察到的相关性表明磁场诱导冷却或记忆装置的潜在应用.
更多相关视频
06:53Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
2.0K
09:06Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
8.1K
相关概念视频
03:02Colors and Magnetism
11.7K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
11.7K
02:42Valence Bond Theory
8.5K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
8.5K
02:58Crystal Field Theory - Octahedral Complexes
26.4K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
26.4K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
42.4K
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
42.4K