Magnetic-Field Response and Giant Electric-Field Modulation of Cu 2 S

• Published in: Nano letters Vol. 24; no. 2; pp. 584 - 591
• Main Authors: Chen, Hongyu, Zhou, Xiaorong, Meng, Ziang, Wang, Xiaoning, Duan, Zhiyuan, Liu, Li, Zhao, Guojian, Yan, Han, Qin, Peixin, Liu, Zhiqi
• Format: Journal Article
• Language: English
• Published: United States 17-01-2024
• Subjects: Impurity phase of LK-99; First-order phase transition; Cu2S; Magnetoresistance; Electroresistance
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.3c03457

Cu
S likely plays an important role in the sharp resistivity transition of LK-99. Nevertheless, this immediately arouses an intriguing question of whether the extraordinary room-temperature colossal magnetoresistance in the initial reports, which has been less focused, originates from Cu
S as well. To resolve this issue, we have systematically investigated the electrical transport and magnetotransport properties of near-stoichiometric Cu
S pellets and thin films. Neither Cu
S nor LK-99 containing Cu
S in this study was found to exhibit the remarkable magnetoresistance effect implied by Lee et al. This implies that Cu
S could not account for all of the intriguing transport properties of the initially reported LK-99, and the initially reported LK-99 samples might contain magnetic impurities. Moreover, based on the crystal-structure-sensitive electrical properties of Cu
S, we have constructed a piezoelectric-strain-controlled device and obtained a giant and reversible resistance modulation of 2 orders of magnitude at room temperature, yielding a huge gauge factor of 160,000.