在BiFeO3-xSrTiO3陶中,电场诱导的非埃尔戈迪克放松剂对铁电过渡产生作用
Leonardo Oliveira1, Jeppe Ormstrup1, Marta Majkut2
1Department of Physics, Technical University of Denmark 2800 Kgs. Lyngby Denmark leosdo@dtu.dk husimo@fysik.dtu.dk.
概括
研究BiFeO3-SrTiO3固体溶液揭示了组成如何影响放松器行为和铁电性质. 了解这些结构-属性关系指导了先进电容材料的开发.
科学领域:
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
- 晶体学 晶体学是指结晶学.
背景情况:
- 基于BiFeO3的固体解决方案对能源应用具有前景.
- 了解结构-属性关系是关键,特别是在相位边界附近的放松特性.
- 在 (100 - x) BiFeO3-xSrTiO3 (BFO-xSTO) 系统中的放松行为需要详细调查.
研究的目的:
- 为了研究BFO-xSTO中组合驱动的放松器状态的作用.
- 了解电场诱导的结构和相位过渡.
- 在电容器应用中,将放松器特性与铁电反应相关联.
主要方法:
- 在双极电场循环下现场同步X射线衍射.
- 通过{111}pc,{200}pc和1/2{311}pc的布拉格峰值监测电场诱导的变化.
- 分析布拉格峰值强度和位置以确定结构动态.
主要成果:
- (111) 和 (111̄) 反射的动力学显示了最初的非厄尔戈迪克状态,随后是铁电排序.
- 在BFO-42STO中,多个站点占用量的增加与更高的临界电场和减少的域重定向有关.
- 两种组合都过渡到铁电状态,但BFO-42STO表现出较弱的反应,由于增加了ergodicity.
结论:
- 构成显著影响BFO-xSTO中的放松器状态和铁电过渡.
- 度在观察到的铁电反应中起着至关重要的作用.
- 这些发现指导了针对特定电容器应用的基于BFO的材料的工程.
相关概念视频
Atomic Nuclei: Nuclear Relaxation Processes
685
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
685
Ferromagnetism
2.4K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
2.4K
Crystal Field Theory - Octahedral Complexes
26.9K
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...
26.9K
Induced Electric Dipoles
4.3K
A permanent electric dipole orients itself along an external electric field. This rotation can be quantified by defining the potential energy because the external torque does work in rotating it. Then, the potential energy is minimum at the parallel configuration and maximum at the antiparallel configuration. While the former is a stable equilibrium, the latter is an unstable equilibrium.
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
4.3K
Atomic Nuclei: Types of Nuclear Relaxation
333
Nuclear relaxation restores the equilibrium population imbalance and can occur via spin–lattice or spin–spin mechanisms, which are first-order exponential decay processes.
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers...
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers...
333
Induced Electric Fields: Applications
1.7K
An important distinction exists between the electric field induced by a changing magnetic field and the electrostatic field produced by a fixed charge distribution. Specifically, the induced electric field is nonconservative because it does not work in moving a charge over a closed path. In contrast, the electrostatic field is conservative and does no net work over a closed path. Hence, electric potential can be associated with the electrostatic field but not the induced field. The following...
1.7K


