采用X射线衍射、电输运和磁化强度测量，结合超晶胞GGA+U计算，研究了不同浓度下La Co $_{1-x}$ Rh $_{x}$ O $_3$钙钛矿系列（$x=0.02-0.5$）中铑的掺杂.证明Co $^{3+}$和Rh $^{3+}$之间没有电荷转移。基于低自旋（LS）态的Co $^{3+}$的LaCoO $_3$的抗磁基态甚至被少量Rh掺杂所干扰。驱动力是与将大Rh $^{3+}$阳离子结合到小LS Co $^{3+}$阳离子的基质中有关的弹性能，其通过在插入的Rh原子的下一个最近位点中形成高自旋（HS）状态的大Co $^{3+}$而弛豫。随着温度的升高，Co $^{3+}$在HS态的布居数通过热激发而增加，在室温附近得到饱和相，该饱和相由小阳离子（LS Co $^{3+}$）和大阳离子（HS Co $^{3+}$和LS Rh $^{3+}$）组成的双钙钛矿结构。的稳定作用的弹性和电子能量的贡献证明在超晶胞计算稀释铑浓度相比，其他掺杂剂与各种三价离子半径。
英文摘要：
The rhodium doping in the LaCo$_{1-x}$Rh$_{x}$O$_3$ perovskite series ($x=0.02-0.5$) has been studied by X-ray diffraction, electric transport and magnetization measurements, complemented by electronic structure GGA+U calculations in supercell for different concentration regimes. No charge transfer between Co$^{3+}$ and Rh$^{3+}$ is evidenced. The diamagnetic ground state of LaCoO$_3$, based on Co$^{3+}$ in low-spin (LS) state, is disturbed even by a small doping of Rh. The driving force is the elastic energy connected with incorporation of a large Rh$^{3+}$ cation into the matrix of small LS Co$^{3+}$ cations, which is relaxed by formation of large Co$^{3+}$ in high-spin (HS) state in the next-nearest sites to the inserted Rh atom. With increasing temperature, the population of Co$^{3+}$ in HS state increases through thermal excitation, and a saturated phase is obtained close to room temperature, consisting of a nearest-neighbor correlation of small (LS Co$^{3+}$) and large (HS Co$^{3+}$ and LS Rh$^{3+}$) cations in a kind of double perovskite structure. The stabilizing role of elastic and electronic energy contributions is demonstrated in supercell calculations for dilute Rh concentration compared to other dopants with various trivalent ionic radius.
Investigation of the Electronic Structure and Spin-State Crossover in LaCoO3 Using Photoemission Spectroscopy
Institute of Physics（印度物理研究所）；Homi Bhabha National Institute（霍米·巴巴国立研究所）；Institute for Solid State Physics, The University of Tokyo（东京大学固体物理研究所）；Deutsches Elektronen-Synchrotron DESY（德国电子同步加速器中心）
On the microscopic origin of the magneto-electronic phase separation in Sr doped LaCoO3
用局域探针研究了掺杂La_（1-x）Sr_xCoO_3钙钛矿的纳米磁电子相分离。相分离是直接观察到的穆斯堡尔谱在所研究的掺杂范围为0.05 <= x <= 0.25在室温下，以及在低温磁相。扩展与当前的同步加速器为基础的X射线光谱，这些数据有助于表征的体积以及不同阶段的局部电和磁性能。基于掺杂Sr离子的随机分布的简单模型很好地描述了分离相的演化以及Co自旋态的变化。实验表明，Sr掺杂引发小液滴和高度掺杂驱动的钴自旋态转变，而无Sr的第二相随着Sr含量的增加而迅速消失。
100 MHz high-speed strain monitor using fiber Bragg grating and optical filter applied for magnetostriction measurements of cobaltite at magnetic fields beyond 100 T
Dynamical Stabilization of Inverted Magnetization and Antimagnons by Spin Injection in an Extended Magnetic System
ETH Zurich（苏黎世联邦理工学院）；Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg（斯特拉斯堡大学，法国国家科学研究中心，斯特拉斯堡材料物理与化学研究所）；Université Grenoble Alpes, CNRS, Institut Néel（格勒诺布尔阿尔卑斯大学，法国国家科学研究中心，尼尔研究所）；University of Konstanz（康斯坦茨大学）
