From antiferromagnetic insulator to ferromagnetic metal: Effects of hydrogen substitution in LaMnAsO
2013; American Physical Society; Volume: 87; Issue: 2 Linguagem: Inglês
10.1103/physrevb.87.020401
ISSN1550-235X
AutoresTaku Hanna, Satoru Matsuishi, Katsuaki Kodama, Toshiya Otomo, Shin‐ichi Shamoto, Hideo Hosono,
Tópico(s)Magnetic and transport properties of perovskites and related materials
ResumoManganese oxyarsenide hydrides LaMnAsO${}_{1\ensuremath{-}x}$H${}_{x}$ ($x=0\ensuremath{-}0.73$) were synthesized by a solid-state reaction under a high pressure of 2 GPa. The hydride ions H${}^{\ensuremath{-}}$ in O${}^{2\ensuremath{-}}$ sites induced an insulator-to-metal conversion and suppressed the antiferromagnetic ordering of Mn spins. Instead, ferromagnetism with negative magnetoresistance was observed. The Curie temperature and saturated moment per Mn increased with $x$ up to 264 K and 1.5\ensuremath{\mu}${}_{\mathrm{B}}$, respectively, at $x=0.73$. These results indicate that H${}^{\ensuremath{-}}$ donate conduction electrons to the MnAs layer, mediating a direct ferromagnetic interaction between Mn atoms.
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