标题： 钡双钙钛矿 Ba$_2$(Cd$_{1-x}$Ca$_x$)ReO$_6$中多极和磁有序的化学压力调控 显示英文标题

标题： Chemical Pressure Tuning of Multipolar and Magnetic Orders in Ba$_2$(Cd$_{1-x}$Ca$_x$)ReO$_6$ Double Perovskites

摘要： 含有5d过渡金属元素的双钙钛矿化合物已被广泛研究作为多极序现象的平台，这些现象源于自旋-轨道耦合的5d电子。 在这项研究中，我们考察了具有5d1电子构型的双钙钛矿固溶体晶体结构、多极序和磁有序之间的相互作用：Ba2CdReO6 和 Ba2CaReO6，它们表现出不同的电子序。 在Ba2CdReO6中，用较大的Ca2+离子替代Cd2+，系统地增加取代量x会导致晶格常数逐渐增大。 尽管自旋-轨道耦合的J = 3/2态在取代过程中保持完整，但在Ba2CdReO6中，Tq = 25 K以下的四极序以及Tm = 12 K以下的倾斜反铁磁（AFM）序随着x的增加而逐步被抑制。 磁化测量显示，倾斜AFM序在x = 0.6时被抑制，并转变为共线AFM序，而四极序在x = 0.9之前仍然存在。 实验得出的电子相图，总结了电子序依赖于晶格常数的关系，与考虑电四极相互作用的理论相图[ G. Chen 等人，Phys. Rev. B 82, 174440 (2010)]非常吻合。 这种一致性证实了由取代引起的化学压力有效地调节了5d电子间的相互作用。 结果表明，化学压力有可能调控多极相互作用，在5d电子系统中开辟了新型多极性质的可能性。 显示英文摘要

摘要： Double perovskite compounds containing 5d transition metal elements have been extensively studied as platforms for multipolar order phenomena stemming from spin-orbit-entangled 5d electrons. In this study, we examine the interplay between crystal structure, multipolar order, and magnetic order in solid solutions of double perovskites with the 5d1 electronic configuration: Ba2CdReO6 and Ba2CaReO6, which exhibit distinct electronic orders. The substitution of larger Ca2+ ions for Cd2+ in Ba2CdReO6, systematically increases the lattice constant with increasing the amount of substitution x. Although the spin-orbit-entangled J = 3/2 state remains intact upon substitution, both the quadrupolar order below Tq = 25 K and the canted antiferro-magnetic (AFM) order below Tm = 12 K in Ba2CdReO6 are progressively suppressed as x increases. Magnetization measurements reveal that the canted AFM order is suppressed at x = 0.6, transitioning to a colinear AFM order, while the quadrupolar order persists up to x = 0.9. The experimental electronic phase diagram, summarizing the dependence of electronic orders on lattice constants, aligns well with the theoretical phase diagram considering electric quadrupolar interactions [G. Chen et al., Phys. Rev. B 82, 174440 (2010)]. This correspondence confirms that chemical pressure induced by substitution effectively tunes the interaction between 5d electrons. The results highlight the potential of chemical pressure to modulate multipolar interactions, paving the way for novel multipolar properties in 5d electron systems.