Discovery of ferromagnetic-half-metal-to-insulator transition in K2Cr8O16

The hollandite chromium oxide K2Cr8O16 has been synthesized in both powder and single-crystal form under high pressure. Combining electrical resistivity, magnetic susceptibility, and x-ray diffraction, we found that K2Cr8O16 is a ferromagnetic metal (or half-metal) with T(C)=180 K and shows a transi...

Full description

Saved in:
Bibliographic Details
Published in:Physical review letters 2009-10, Vol.103 (14), p.146403-146403
Main Authors: Hasegawa, Kunihiro, Isobe, Masahiko, Yamauchi, Touru, Ueda, Hiroaki, Yamaura, Jun-Ichi, Gotou, Hirotada, Yagi, Takehiko, Sato, Hirohiko, Ueda, Yutaka
Format: Article
Language:English
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The hollandite chromium oxide K2Cr8O16 has been synthesized in both powder and single-crystal form under high pressure. Combining electrical resistivity, magnetic susceptibility, and x-ray diffraction, we found that K2Cr8O16 is a ferromagnetic metal (or half-metal) with T(C)=180 K and shows a transition to an insulator at 95 K without any apparent structural change but retaining ferromagnetism. K2Cr8O16 is quite unique in three aspects: It has a rare mixed valence of Cr3+ and Cr4+; it has a metal (or half-metal)-to-insulator transition in a ferromagnetic state; and the resulting low-temperature phase is a rare case of a ferromagnetic insulator. This discovery could open a new frontier on the relation of magnetism and conducting properties in strongly correlated electron systems.
ISSN:1079-7114
DOI:10.1103/PhysRevLett.103.146403