Correlation‐Driven Magnetic Frustration and Insulating Behavior of TiF 3
Correlation‐Driven Magnetic Frustration and Insulating Behavior of TiF 3
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相关性 — TiF 3 驱动的磁阻和绝缘行为
DOI：
10.1002/pssr.202300330
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发表时间：
2024
期刊：
影响因子：
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通讯作者：
Geilhufe, Richard Matthias
中科院分区：
文献类型：
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作者：
Fernando, Gayanath W.;Sheets, Donal;Hancock, Jason;Ernst, Arthur;Geilhufe, Richard Matthias
卤化物钙钛矿TiF 3，著名的结构，电子相关性，磁性和热膨胀之间的复杂的相互作用，进行了研究。尽管其结构简单，但了解其低温磁性行为一直是一个挑战。以前的理论提出反铁磁有序。相比之下，在低至10 K的温度下，不存在有序磁态的实验特征。目前的研究成功地重新评估了TiF 3的理论模型，揭示了强电子相关性作为其绝缘行为和磁挫折的关键驱动因素的重要性。此外，频率依赖的光学反射率测量显示出绝缘状态的明显迹象。计算的磁性数据的分析给出了一个反铁磁交换耦合与净韦斯温度为25 K的顺序，以及符合的磁响应与每Ti 3+的aS= 1/2本地矩。然而，该系统在此温度范围内没有显示出磁化率峰，并且在低至1 K时似乎没有长程反铁磁序。将材料的从头算建模扩展到更大的晶胞显示出松弛成非共线磁有序的趋势，在几个磁基态之间具有浅能量景观，促进了这种简单的、近立方钙钛矿结构材料作为候选自旋液体的状态。
The halide perovskite TiF3, renowned for its intricate interplay between structure, electronic correlations, magnetism, and thermal expansion, is investigated. Despite its simple structure, understanding its low‐temperature magnetic behavior has been a challenge. Previous theories propose antiferromagnetic ordering. In contrast, experimental signatures for an ordered magnetic state are absent down to 10 K. The current study has successfully reevaluated the theoretical modeling of TiF3, unveiling the significance of strong electronic correlations as the key driver for its insulating behavior and magnetic frustration. In addition, frequency‐dependent optical reflectivity measurements exhibit clear signs of an insulating state. The analysis of the calculated magnetic data gives an antiferromagnetic exchange coupling with a net Weiss temperature of order 25 K as well as a magnetic response consistent with aS= 1/2 local moment per Ti3+. Yet, the system shows no susceptibility peak at this temperature scale and appears free of long‐range antiferromagnetic order down to 1 K. Extending ab initio modeling of the material to larger unit cells shows a tendency for relaxing into a noncollinear magnetic ordering, with a shallow energy landscape between several magnetic ground states, promoting the status of this simple, nearly cubic perovskite structured material as a candidate spin liquid.