Magnetism and Correlated Electrons in LaCr$_2$Ge$_2$N

Jiao-Jiao Meng; Yu-Sen Xiao; Gen Li; Shao-Hua Liu; Bai-Zhuo Li; Hao Jiang; Zhen Yu; Yi-Qiang Lin; Xin-Yu Zhao; Qing-Chen Duan; Wu-Zhang Yang; Chong-Yao Zhao; Zhi Ren; Yu-Xue Mei; Yong-Liang Chen; Rui-Dan Zhong; Qing-Xin Dong; Peng-Tao Yang; Shu-Gang Tan; Bo-Sen Wang; Huiqian Luo; Jin-Guang Cheng; Xue Ming; Cao Wang; Guang-Han Cao

doi:10.1103/2twh-qbdn

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arXiv · 2512.20843

Magnetism and Correlated Electrons in LaCr$_2$Ge$_2$N

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Abstract

We report the synthesis, structure and physical properties of a new quaternary nitride LaCr$_2$Ge$_2$N. The compound crystallizes in the CeCr$_2$Si$_2$C-type structure (P4/mmm), featuring distinctive Cr$_2$N square sheets within Cr$_2$Ge$_2$N block layers. Physical characterizations reveal enhanced electron correlations evidenced by a Sommerfeld coefficient substantially larger than band calculations and pressure-induced deviation from Fermi-liquid behavior. Magnetic measurements show short-range antiferromagnetic correlations developing around 460 K, followed by long-range magnetic ordering at 14 K. Additionally, subtle anomalies at 378 K suggest possible electronic ordering. First-principles calculations reveal nearly-flat Cr-3d bands near the Fermi level and predict a striped antiferromagnetic ground state. This work demonstrates how electron count variation in the CeCr$_2$Si$_2$C-type structure family leads to magnetic ordering in LaCr$_2$Ge$_2$N, contrasting with the paramagnetic behavior of LnCr$_2$Si$_2$C compounds.

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Jiao-Jiao Meng, Yu-Sen Xiao, Gen Li, Shao-Hua Liu, Bai-Zhuo Li, Hao Jiang, Zhen Yu, Yi-Qiang Lin, Xin-Yu Zhao, Qing-Chen Duan, Wu-Zhang Yang, Chong-Yao Zhao, Zhi Ren, Yu-Xue Mei, Yong-Liang Chen, Rui-Dan Zhong, Qing-Xin Dong, Peng-Tao Yang, Shu-Gang Tan, Bo-Sen Wang, Huiqian Luo, Jin-Guang Cheng, Xue Ming, Cao Wang, Guang-Han Cao. 2025-12-23. Magnetism and Correlated Electrons in LaCr$_2$Ge$_2$N. https://doi.org/10.1103/2twh-qbdn

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