Increased room temperature ferromagnetism in Co-doped tetrahedral perovskite niobates.

ABSTRACT: Dilute magnetic semiconductors (DMSs), such as (In, Mn)As and (Ga, Mn)As prototypes, are limited to III-V semiconductors with Curie temperatures (T _c) far from room temperature, thereby hindering their wide application. Here, one kind of DMS based on perovskite niobates is reported. BaM _x Nb_(1-x)O_3-δ (M = Fe, Co) powders are prepared by the composite-hydroxide-mediated method. The addition of M elements endows BaM _x Nb_(1-x)O_3-δ with local ferromagnetism. The tetragonal BaCo _x Nb_(1-x)O_3-δ nanocrystals can be obtained by Co doping, which shows strong saturation magnetization (M _sat) of 2.22 emu g^-1, a remnant magnetization (M _r) of 0.084 emu g^-1 and a small coercive field (H _c) of 167.02 Oe at room temperature. The ab initio calculations indicate that Co doping could lead to a 64% local spin polarization at the Fermi level (E _F) with net spin DOS of 0.89 electrons eV^-1, this result shows the possibility of maintaining strong ferromagnetism at room temperature. In addition, the trade-off effect between the defect band absorption and ferromagnetic properties of BaM _x Nb_(1-x)O_3-δ is verified experimentally and theoretically.

SUBMITTER: Zhou Y 

PROVIDER: S-EPMC8493198 | biostudies-literature | 2021 Oct

REPOSITORIES: biostudies-literature