Low-field colossal magnetoresistance in bandwidth-controlled manganites

Journal Article · Tue Apr 01 04:00:00 EST 1997 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.364707· OSTI ID:554266

Kuwahara, H; Moritomo, Y; Tomioka, Y; Asamitsu, A; Kasai, M ^[1]; Tokura, Y ^[1]

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1. Joint Research Center for Atom Technology (JRCAT), Tsukuba 305 (Japan)

We have investigated magnetoresistance (MR) phenomena relevant to the charge ordering (CO), namely, the real space ordering of both Mn{sup 3+} and Mn{sup 4+}, in single crystals of (Nd{sub 1{minus}y}Sm{sub y}){sub 1/2}Sr{sub 1/2}MnO{sub 3}, in which the one-electron bandwidth {ital (W)} is systematically controlled by varying the average ionic radius of the {ital A} site. The low-field colossal MR is observed for the small-{ital W} region of y{ge}0.5; e.g., {rho}(0)/{rho}(H){gt}10{sup 3} in a field of 0.4 T at 115 K for the y=0.94 crystal. This is viewed as a first-order insulator-to-metal phase transition induced by a magnetic field, which accompanies a lattice-structural change. In the small-{ital W} region, the CO instability accompanying the antiferromagnetic spin correlations subsists even above the ferromagnetic transition temperature T{sub c}. The competition between the ferromagnetic double-exchange and antiferromagnetic CO interactions gives rise to such a lattice-coupled first-order phase transition induced by a relatively low magnetic field. {copyright} {ital 1997 American Institute of Physics.}

• OSTI ID: 554266
• Report Number(s): CONF-961141--
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 81; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ELECTRIC CONDUCTIVITY
FERROMAGNETIC MATERIALS
MAGNETISM
MAGNETORESISTANCE
MANGANESE OXIDES
MONOCRYSTALS
NEODYMIUM OXIDES
PHASE TRANSFORMATIONS
SAMARIUM OXIDES
STRONTIUM OXIDES