论文标题
温度诱导的价呈钙钛矿BA2-XSRXTBIRO6中的价状态过渡
Temperature-induced valence-state transition in double perovskite Ba2-xSrxTbIrO6
论文作者
论文摘要
在这项工作中，在狭窄的构图范围内研究了温度引起的价态状态过渡，该范围为ba $ _ {2-x} $ sr $ _x $ _x $ tbiro $ _6 $。 Valence状态过渡涉及TB和IR之间的电子转移，从而导致TB $^{3+} $/IR $^{5+} $和TB $^{4+} $/IR $^{4+} $阶段之间的价变化。该一阶转变对TB和IR离子的低温下的晶格，运输特性和远距离磁顺序具有巨大影响。 ir $^{5+} $ ion的电子配置为5 $ d^4 $（$ j \ rm_ {eff} $ = 0），预计是非磁性的。相反，IR $^{4+} $ ion的配置为5 $ d^5 $（$ j \ rm_ {eff} $ = 1/2）有利于长距离磁性顺序。 For $x$ = 0.1 with Tb$^{3+}$/Ir$^{5+}$ configuration to the lowest temperature (2 K) investigated in this work, a spin-glass behavior is observed around 5 K indicating Ir$^{5+}$ ($J\rm_{eff}$ = 0) ions act as a spacer reducing the magnetic interactions between Tb$^{3+}$ ions.对于$ x $ = 0.5，带有tb $^{4+} $/ir $^{4+} $配置以下这项工作的最高温度低于最高温度，以$ t \ rm_n $ = 40 K的远程反磁性顺序被观察到了强调IR $ $ $ $^{4+} $ j {4+}的重要性，结核病和红外离子的顺序。对于0.2 $ \ leqslant x \ leqslant $ 0.375，温度引起的价值状态从高温tb $^{3+} $^{3+} $/ir $^{5+} $相位到低温tb $^{4+} \ leqslant $ 325 K，过渡温度随$ x $升高。组成依赖性证明了$ x $的关键区域的价状态调整的能力，从而导致磁性和结构的同时变化。可以在薄膜中使用合适的应变来使用这种调整能力，以便在操纵磁力时充当开关。
In this work, a temperature-induced valence-state transition is studied in a narrow composition range of Ba$_{2-x}$Sr$_x$TbIrO$_6$. The valence-state transition involves an electron transfer between Tb and Ir leading to the valence-state change between Tb$^{3+}$/Ir$^{5+}$ and Tb$^{4+}$/Ir$^{4+}$ phases. This first-order transition has a dramatic effect on the lattice, transport properties, and the long-range magnetic order at low temperatures for both Tb and Ir ions. Ir$^{5+}$ ion has an electronic configuration of 5$d^4$ ($J\rm_{eff}$ = 0) which is expected to be nonmagnetic. In contrast, Ir$^{4+}$ ion with a configuration of 5$d^5$($J\rm_{eff}$ = 1/2) favors a long-range magnetic order. For $x$ = 0.1 with Tb$^{3+}$/Ir$^{5+}$ configuration to the lowest temperature (2 K) investigated in this work, a spin-glass behavior is observed around 5 K indicating Ir$^{5+}$ ($J\rm_{eff}$ = 0) ions act as a spacer reducing the magnetic interactions between Tb$^{3+}$ ions. For $x$ = 0.5 with Tb$^{4+}$/Ir$^{4+}$ configuration below the highest temperature 400 K of this work, a long-range antiferromagnetic order at $T\rm_N$ = 40 K is observed highlighting the importance of Ir$^{4+}$ ($J\rm_{eff}$ = 1/2) ions in promoting the long-range magnetic order of both Tb and Ir ions. For 0.2 $\leqslant x \leqslant$ 0.375, a temperature-induced valence-state transition from high-temperature Tb$^{3+}$/Ir$^{5+}$ phase to low-temperature Tb$^{4+}$/Ir$^{4+}$ phase occurs in the temperature range 180 K $\leqslant T \leqslant$ 325 K and the transition temperature increases with $x$. The compositional dependence demonstrates the ability to tune the the valence state for a critical region of $x$ that leads to a concurrent change in magnetism and structure. This tuning ability could be employed with suitable strain in thin films to act as a switch as the magnetism is manipulated.
