scholarly journals Soft antiphase tilt of oxygen octahedra in the hybrid improper multiferroic Ca3Mn1.9Ti0.1O7

2018 ◽  
Vol 97 (4) ◽  
Author(s):  
Feng Ye ◽  
Jinchen Wang ◽  
Jieming Sheng ◽  
C. Hoffmann ◽  
T. Gu ◽  
...  
Keyword(s):  
Oxygen Octahedra

Crystallographic studies of olivine-related sarcopside-type solid solutions

1984 ◽  
Vol 166 (3-4) ◽  
Author(s):  
Anders G. Nord
Keyword(s):  
Solid Solutions ◽  
Cation Distribution ◽  
Oxygen Octahedra ◽  
Size And Shape

AbstractSolid solutions ofThe cation distribution results are compared with corresponding results for olivines, orthopyroxenes, and some other oxosalt structures with metal-oxygen octahedra similar in size and shape to those in olivine. It is concluded that the Ni

scholarly journals On the incorporation of nickel into hexagonal barium titanate: magnetic properties and electron paramagnetic resonance (EPR)

2020 ◽  
Vol 56 (8) ◽  
pp. 4967-4978
Author(s):  
R. Böttcher ◽  
H. T. Langhammer ◽  
T. Walther ◽  
S. Kücker ◽  
S. G. Ebbinghaus
Keyword(s):  
Magnetic Properties ◽  
Barium Titanate ◽  
Paramagnetic Susceptibility ◽  
Oxygen Octahedra ◽  
Temperature Dependent ◽  
Paramagnetic Resonance ◽  
Forbidden Transition ◽  
The Face ◽  
Crystal Field Parameters ◽  
Electron Paramagnetic

AbstractSystematic measurements of the magnetic moment of hexagonal 6H-BaTiO3 + 0.04 BaO + x NiO (0.005 ≤ x ≤ 0.02) ceramics were performed to study the influence of Ni ions on the magnetic properties. By temperature-dependent measurements of the paramagnetic susceptibility at 90 kOe, the Ni2+ ion was identified as the majority defect in air-sintered Ni-doped hexagonal barium titanate. Q-band EPR investigations of a 2.0 mol% Ni-doped single crystal revealed three different Ni centers located at Ti sites: first, Ni3+ ions at Ti sites in intact oxygen octahedra, second, Ni3+ associated with an oxygen vacancy and third, the presence of Ni2+ centers leading to a forbidden transition. The Ni3+—VO associate characterized by a vacancy in the face-sharing oxygen plane of the oxygen octahedra can be ruled out. The crystal field parameters of the Ni2+ defect were estimated by a combined fitting of the paramagnetic susceptibility and the EPR fine structure parameter D to $$B_{0}^{4}$$ B 0 4 ≈ −17,300 cm−1, $$\left| {B_{0}^{2} } \right|$$ B 0 2 ≈ 2500 cm−1 and $$B_{3}^{4}$$ B 3 4 ≈ 19,000 cm−1.

Importance of oxygen octahedra tilts for the electron-phonon coupling in K-doped BaBiO3

2013 ◽  
Vol 88 (22) ◽  
Author(s):  
Timur Bazhirov ◽  
Sinisa Coh ◽  
Steven G. Louie ◽  
Marvin L. Cohen
Keyword(s):  
Oxygen Octahedra ◽  
Phonon Coupling ◽  
Electron Phonon Coupling

scholarly journals Robust manipulation of magnetism in LaAO3/BaTiO3 (A = Fe, Mn and Cr) superstructures by ferroelectric polarization

IUCrJ ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 189-196 ◽  
Author(s):  
Dong Chen ◽  
Guangbiao Zhang ◽  
Zhenxiang Cheng ◽  
Shuai Dong ◽  
Yuanxu Wang
Keyword(s):  
Magnetic Ordering ◽  
Exchange Interactions ◽  
Perovskite Oxide ◽  
Oxygen Octahedra ◽  
Ferroelectric Polarization ◽  
Structural Basis ◽  
Generalized Gradient ◽  
Metallic Behavior ◽  
Spin Orbital ◽  
Ferromagnetic Ordering

Robust control of magnetism is both fundamentally and practically meaningful and highly desirable, although it remains a big challenge. In this work, perovskite oxide superstructures LaFeO3/BaTiO3 (LFO/BTO), LaMnO3/BaTiO3 (LMO/BTO) and LaCrO3/BaTiO3 (LCO/BTO) (001) are designed to facilitate tuning of magnetism by the electric field from ferroelectric polarization, and are systemically investigated via first-principles calculations. The results show that the magnetic ordering, conductivity and exchange interactions can be controlled simultaneously or individually by the reorientation of the ferroelectric polarization of BTO in these designed superstructures. Self-consistent calculations within the generalized gradient approximation plus on-site Coulomb correction did not produce distinct rotations of oxygen octahedra, but there were obvious changes in bond length between oxygen and the cations. These changes cause tilting of the oxygen octahedra and lead to spin, orbital and bond reconstruction at the interface, which is the structural basis responsible for the manipulation. With the G-type antiferromagnetic (G-AFM) ordering unchanged for both ±P cases, a metal–insulator transition can be observed in the LFO/BTO superstructure, which is controlled by the LFO thin film. The LMO/BTO system has A-type antiferromagnetic (A-AFM) ordering with metallic behavior in the +P case, while it shifts to a half-metallic ferromagnetic ordering when the direction of the polarization is switched. LCO/BTO exhibits C-type antiferromagnetic (C-AFM) and G-AFM orders in the +P and −P cases, respectively. The three purpose-designed superstructures with robust intrinsic magnetoelectric coupling are a particularly interesting model system that can provide guidance for the development of this field for future applications.

Sign in / Sign up

Export Citation Format

Share Document