Insulator-metal-superconductor transition in medium-entropy van der Waals compound MEPSe3 (ME=Fe, Mn, Cd, and In) under high pressures
| Autor: | Chen, Xu, Wang, Junjie, Ying, Tianping, Huang, Dajian, Gou, Huiyang, Zhang, Qinghua, Li, Yanchun, Hosono, Hideo, Guo, Jian-gang, Chen, Xiaolong |
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| Rok vydání: | 2022 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.106.184502 |
| Popis: | MPX3 (M=metals, X=S or Se) represents a large family of van der Waals (vdW) materials featuring with P-P dimers of ~2.3 {\AA} separation. Its electrical transport property and structure can hardly be tuned by the intentional chemical doping and ionic intercalation. Here, we employ an entropy-enhancement strategy to successfully obtain a series of medium-entropy compounds MEPSe3 (ME=Fe, Mn, Cd and In), in which the electrical and magnetic properties changed simultaneously. Lone-pair electrons of P emerge due to the dissociation of the dimers as evidenced by a 35% elongation in the P-P interatomic distance. The band gap widens from 0.1 eV to 0.7 eV by this dissociation. Under external physical pressure up to ~50 GPa, a giant collapse of up to 15% in the c-axis happens, which is in contrast to the in-plane shrinkage of their counterparts Fe/MnPSe3. It leads to the recombination of P3- with lone pair electrons into a P-P dimer and the smallest bulk modulus of 28 GPa in MPX3. The MEPSe3 transits from a spin-glass insulator to metal, and to superconductor, which is rarely observed in the MPX3. Our findings highlight the P-P dimer as an indicator to probe diverse electronic structure and the effectiveness of entropy-enhancement in materials science. Comment: 10 pages, 4 figures |
| Databáze: | arXiv |
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