Liu, Z.; Zhang, S.; Wang, X.; Ye, X.; Qin, S.; Shen, X.; Lu, D.; Dai, J.; Cao, Y.; Chen, K.; Radu, F.; Wu, W.-B.; Chen, C.-T.; Francoual, S.; Mardegan, J.R. L.; Leupold, O.; Tjeng, L.H.; Hu, Z.; Yang, Y.; Long, Y.: Realization of a Half Metal with a Record-High Curie Temperature in Perovskite Oxides. Advanced Materials 34 (2022), p. 2200626/1-8
10.1002/adma.202200626
Abstract:
Half metals, in which one spin channel is conducting while the other is insulating with an energy gap, are theoretically considered to comprise 100% spin-polarized conducting electrons, and thus have promising applications in high-efficiency magnetic sensors, computer memory, magnetic recording, and so on. However, for practical applications, a high Curie temperature combined with a wide spin energy gap and large magnetization is required. Realizing such a high-performance combination is a key challenge. Herein, a novel A- and B-site ordered quadruple perovskite oxide LaCu3Fe2Re2O12 with the charge format of Cu2+/Fe3+/Re4.5+ is reported. The strong Cu2+(↑)Fe3+(↑)Re4.5+(↓) spin interactions lead to a ferrimagnetic Curie temperature as high as 710 K, which is the reported record in perovskite-type half metals thus far. The saturated magnetic moment determined at 300 K is 7.0 μB f.u.−1 and further increases to 8.0 μB f.u.−1 at 2 K. First-principles calculations reveal a half-metallic nature with a spin-down conducting band while a spin-up insulating band with a large energy gap up to 2.27 eV. The currently unprecedented realization of record Curie temperature coupling with the wide energy gap and large moment in LaCu3Fe2Re2O12 opens a way for potential applications in advanced spintronic devices at/above room temperature.