稀磁半导体(BaNa)(ZnMn)2As2中的散铁磁性研究
(Asperomagnetic order in diluted magnetic semiconductor (Ba,Na)(Zn,Mn)2As2 )
G. X. Gu, G. Q. Zhao, C. J. Lin, Y. Q. Li, C. Q. Jin and G. Xiang
Appl. Phys. Lett. 112, 032402 (2018)
We report an investigation of magnetic ordering in (Ba,Na)(Zn,Mn)2As2 (BNZMA) single crystals, a type of II-II-V magnetic semiconductor based on BaZn2As2, with a combination of magnetic, electron transport, and spin polarization measurements. At temperatures above 90 K, the susceptibility is found to follow the Curie-Weiss law with a Curie-Weiss temperature of 16 K. At low temperatures, both the dc and ac susceptibilities exhibit spin-glass-like features and the electron spin polarization is determined to be 48±8% using Andreev reflection spectroscopy. Our experimental results suggest that the ground state of BNZMA has an asperomagnetic order, an intermediate regime between a ferromagnet and a canonical spin glass. Such a partially spin polarized glassy phase can be attributed to the competition between the short range antiferromagnetic superexchange interaction and the long range ferromagnetic/antiferromagnetic exchange interactions mediated by high-density holes.