Transport and magnetism correlations in thin-film ferromagnetic oxides

Journal Article · Sun Mar 31 23:00:00 EST 1996 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.361715· OSTI ID:279986

Hundley, M F; Neumeier, J J; Heffner, R H; Jia, Q X; Wu, X D; Thompson, J D ^[1]

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1. Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

To determine the {ital T}{sub {ital c}} dependence of the colossal magnetoresistance (CMR) exhibited by the ferromagnetic La{sub 0.7}A{sub 0.3}MnO{sub 3+{delta}} (A=Ba, Ca, Sr) system, we examine the magnetic-field and temperature-dependent resistivity and magnetization of a series of thin films that were grown via pulsed-laser deposition. The films had magnetic ordering temperatures ({ital T}{sub {ital c}}) ranging from 150 to 350 K. All samples display a large negative MR that is largest near {ital T}{sub {ital c}}, and samples with a low {ital T}{sub {ital c}} display significantly larger MR values than do samples with large {ital T}{sub {ital c}}{close_quote}s. The quantity {rho}({ital T}{sub {ital c}})/{rho}(4 K), the amount by which the resistivity is reduced by full ferromagnetic order, varies as exp({ital E}{sub {ital a}}/{ital T}{sub {ital c}}) with an activation energy {ital E}{sub {ital a}}=0.1 eV. These results indicate that the magnitude of the CMR effect in a given specimen is controlled not by {rho}({ital T}{sub {ital c}}), but by {ital T}{sub {ital c}} via the ratio {rho}({ital T}{sub {ital c}})/{rho}(4 K). Phenomenological scaling relationships are also reported that link {rho}({ital H},{ital T}) to both {ital H} and {ital M}({ital H},{ital T}). {copyright} {ital 1996 American Institute of Physics.}

• OSTI ID: 279986
• Report Number(s): CONF-951101--
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 79; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
BARIUM OXIDES
CALCIUM OXIDES
ENERGY BEAM DEPOSITION
FERROMAGNETIC MATERIALS
LANTHANUM OXIDES
LASER RADIATION
MAGNETIZATION
MAGNETORESISTANCE
MANGANESE OXIDES
SCALING LAWS
STRONTIUM OXIDES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0000-0013 K
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
THIN FILMS