A family of rare-earth Quasi-One-Dimensional spin-chain compounds K2RENb5O15 (RE=Ce,Pr,Nd,Sm,Gd-Ho) with large interchain distance

Qingyuan Zeng; Han Ge; Maofeng Wu; Shaoheng Ruan; Tiantian Li; Zhaosheng Wang; Jingxin Li; Langsheng Ling; Wei Tong; Shuai Huang; Andi Liu; Jin Zhou; Zhengcai Xia; Jieming Sheng; Liusuo Wu; Zhaoming Tian

arXiv · 2401.11091

A family of rare-earth Quasi-One-Dimensional spin-chain compounds K2RENb5O15 (RE=Ce,Pr,Nd,Sm,Gd-Ho) with large interchain distance

Qingyuan Zeng·Han Ge·Maofeng Wu·Shaoheng Ruan·Tiantian Li·Zhaosheng Wang·Jingxin Li·Langsheng Ling·Wei Tong·Shuai Huang·Andi Liu·Jin Zhou·Zhengcai Xia·Jieming Sheng·Liusuo Wu·Zhaoming Tian

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Abstract

One-dimensional spin chain systems have received special attention to discover the novel magnetic ground states and emergent phenomena, while the magnetic studies on rare-earth (RE)-based 1D spin chain materials are still rare. Here, we report the synthesis, structure and magnetic behaviors on a family of tetragonal tungsten-bronze structure K2RENb5O15 (RE = Ce, Pr, Nd, Sm, Gd-Ho) compounds, which consist of 1D linear spin-chain structure built by RE3+ ions along the c-axis and well spatially separated by the nonmagnetic K/Nb-O polyhedrons with large interchain distances of ~ 8.80-8.88 {\AA} in the ab-plane. The low temperature magnetic measurements reveal the absence of long-range magnetic order down to 1.8 K for all serial K2RENb5O15 compounds and the dominant ferromagnetic interactions for RE=Ce,Dy and antiferromagnetic interactions for other members. Among them, K2GdNb5O15 with spin only magnetic moment S=7/2, exhibits a long-range magnetic order with TN~0.31 K and strong spin fluctuations at low temperatures due to its low-dimension characteristics. Moreover, a large magnetocaloric effect under low field change of 0-2 T is realized at temperatures below 1 K for K2GdNb5O15, letting it as an ideal candidate for adiabatic magnetic refrigeration applications at sub-kelvin temperatures. The K2RENb5O15 become a rare family of insulting RE-based magnets to explore the novel 1D spin chain physics beyond the 3d TM-based counterparts, in terms of its combination of low dimension, strong spin-orbital coupling and the rich diversity of RE ions.

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Qingyuan Zeng, Han Ge, Maofeng Wu, Shaoheng Ruan, Tiantian Li, Zhaosheng Wang, Jingxin Li, Langsheng Ling, Wei Tong, Shuai Huang, Andi Liu, Jin Zhou, Zhengcai Xia, Jieming Sheng, Liusuo Wu, Zhaoming Tian. 2024-01-20. A family of rare-earth Quasi-One-Dimensional spin-chain compounds K2RENb5O15 (RE=Ce,Pr,Nd,Sm,Gd-Ho) with large interchain distance. https://arxiv.org/abs/2401.11091

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