TY - JOUR
T1 - Magnetoresistance in spinel-type MgxCu1-xCr 2S4
AU - Kamihara, Y.
AU - Matoba, M.
AU - Kyomen, T.
AU - Itoh, M.
N1 - Funding Information:
One (M.M.) of us is indebted to Prof. G.A. Sawatzky (University of Groningen) for his helpful advises during the stay in his laboratory. One (Y.K.) of us was financialy supported by a Grant-in-Aid for the 21st century COE program ‘Keio Optical and Electronic Device Technology for Access Network’ from the Ministry of Education, Culture, Sports, Science, and Technology, Japan. This work was partially supported by the Research Grants of Keio University and performed under Collaborative Research Project of Materials and Structures Laboratory, Tokyo Institute of Technology.
PY - 2004/10
Y1 - 2004/10
N2 - CuCr2S4 shows a p-type metallic conductivity and ferromagnetism with Curie temperatures Tc of 375 K, and exhibit magnetic anomaly at 84 K (= Tm). CuCr2S4 exhibits the coexistence of both the ferromagnetism and spin-glass with the irreversible magnetic effect below Tm. The partial 20% Mg-substitution for Cu in CuCr2S4 slightly reduces the Tc and Tm. Magnetorsistance of MgxCu 1-xCr2S4 can be expressed as Δp=aH 2-bHn below Tm. a, b, and n are temperature-dependent adjustable parameters. These unique MR behavior would be attributed to the coexistence of the ferromagnetism and spin-glass-like order below Tm, Mg-substitution decreased the conducting carrier, which forms the conduction band whose orbital motion gave the positive MR contribution. Therefore, Mg-substitution gave smaller positive MR contribution and consequently gave larger negative MR (maximum 7% at 10 K) in Mg 0.2Cu0.8Cr2S4. These results suggest that Cr 3d band filling control can be expected to give functional magnetoelectric transport properties in CuCr2S4.
AB - CuCr2S4 shows a p-type metallic conductivity and ferromagnetism with Curie temperatures Tc of 375 K, and exhibit magnetic anomaly at 84 K (= Tm). CuCr2S4 exhibits the coexistence of both the ferromagnetism and spin-glass with the irreversible magnetic effect below Tm. The partial 20% Mg-substitution for Cu in CuCr2S4 slightly reduces the Tc and Tm. Magnetorsistance of MgxCu 1-xCr2S4 can be expressed as Δp=aH 2-bHn below Tm. a, b, and n are temperature-dependent adjustable parameters. These unique MR behavior would be attributed to the coexistence of the ferromagnetism and spin-glass-like order below Tm, Mg-substitution decreased the conducting carrier, which forms the conduction band whose orbital motion gave the positive MR contribution. Therefore, Mg-substitution gave smaller positive MR contribution and consequently gave larger negative MR (maximum 7% at 10 K) in Mg 0.2Cu0.8Cr2S4. These results suggest that Cr 3d band filling control can be expected to give functional magnetoelectric transport properties in CuCr2S4.
KW - A. Chalcogen
KW - A. Thiospinel
KW - D. Double exchange interaction
KW - D. Magnetoresistance
KW - D. Room temperature ferromagnetism
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U2 - 10.1016/j.ssc.2004.07.034
DO - 10.1016/j.ssc.2004.07.034
M3 - Article
AN - SCOPUS:4444244728
VL - 132
SP - 247
EP - 251
JO - Solid State Communications
JF - Solid State Communications
SN - 0038-1098
IS - 3-4
ER -