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Title: Characterization of films of La{sub 1{minus}x}Sr{sub x}MnO{sub 3{minus}{delta}} grown by means of metal organic chemical vapor deposition

Abstract

An effort to develop La manganites for possible sensor applications has led to the successful growth of La{sub 1{minus}x}B{sub x}MnO{sub 3{minus}{delta}} (B=Sr, Ca) thin films on single crystal MgO, Al{sub 2}O{sub 3}, and LaAlO{sub 3} substrates. Here we concentrate on Sr-doped material on LaAlO{sub 3} with Curie temperature T{sub c}=262{plus_minus}2 K. T{sub c} was determined from magnetization measurements using Arrott plots, and agrees well with the observed resistivity peak in zero applied magnetic field (H). This T{sub c} corresponds closely to a Sr content x=0.17 reported in bulk materials. At H=60 kOe the maximum magnetoresistance {Delta}{rho}/{rho}{approx}0.95. No discernible hysteresis, as might be expected for structural phase transitions, was observed. When plotted as a function of reduced temperature T/T{sub c}, the magnetization extrapolated to zero H is best fit by a Brillouin function with an effective spin value {l_angle}S{r_angle} much larger than the {l_angle}S{r_angle}=1.9 indicated by the composition. This may be indicative of magnetic polaron formation, especially near the magnetic and transport transition temperatures. At temperatures far below T{sub c} there is an increase in resistivity of the thin films, which is considerably modified by the application of a field of 50 kOe. The conductivity, however, remains finite as the temperaturemore » approaches zero, indicating transport in states close to but above the mobility edge. {copyright} {ital 1997 American Institute of Physics.}« less

Authors:
; ; ; ; ;  [1]
  1. MARTECH, the Florida State University, Tallahassee, Florida 32306-4000 (United States)
Publication Date:
OSTI Identifier:
496540
Report Number(s):
CONF-961141-
Journal ID: JAPIAU; ISSN 0021-8979; TRN: 97:016233
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 81; Journal Issue: 8; Conference: 41. annual conference on magnetism and magnetic materials, Atlanta, GA (United States), 12-15 Nov 1996; Other Information: PBD: Apr 1997
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; LANTHANUM OXIDES; MAGNETIZATION; STRONTIUM OXIDES; MANGANESE OXIDES; LANTHANUM COMPOUNDS; STRONTIUM COMPOUNDS; FERROMAGNETIC MATERIALS; CURIE POINT; THIN FILMS; TEMPERATURE DEPENDENCE; CHEMICAL VAPOR DEPOSITION; MAGNETORESISTANCE

Citation Formats

Heremans, J J, Carris, M, Watts, S, Yu, X, Dahmen, K H, and von Molnar, S. Characterization of films of La{sub 1{minus}x}Sr{sub x}MnO{sub 3{minus}{delta}} grown by means of metal organic chemical vapor deposition. United States: N. p., 1997. Web. doi:10.1063/1.365014.
Heremans, J J, Carris, M, Watts, S, Yu, X, Dahmen, K H, & von Molnar, S. Characterization of films of La{sub 1{minus}x}Sr{sub x}MnO{sub 3{minus}{delta}} grown by means of metal organic chemical vapor deposition. United States. https://doi.org/10.1063/1.365014
Heremans, J J, Carris, M, Watts, S, Yu, X, Dahmen, K H, and von Molnar, S. Tue . "Characterization of films of La{sub 1{minus}x}Sr{sub x}MnO{sub 3{minus}{delta}} grown by means of metal organic chemical vapor deposition". United States. https://doi.org/10.1063/1.365014.
@article{osti_496540,
title = {Characterization of films of La{sub 1{minus}x}Sr{sub x}MnO{sub 3{minus}{delta}} grown by means of metal organic chemical vapor deposition},
author = {Heremans, J J and Carris, M and Watts, S and Yu, X and Dahmen, K H and von Molnar, S},
abstractNote = {An effort to develop La manganites for possible sensor applications has led to the successful growth of La{sub 1{minus}x}B{sub x}MnO{sub 3{minus}{delta}} (B=Sr, Ca) thin films on single crystal MgO, Al{sub 2}O{sub 3}, and LaAlO{sub 3} substrates. Here we concentrate on Sr-doped material on LaAlO{sub 3} with Curie temperature T{sub c}=262{plus_minus}2 K. T{sub c} was determined from magnetization measurements using Arrott plots, and agrees well with the observed resistivity peak in zero applied magnetic field (H). This T{sub c} corresponds closely to a Sr content x=0.17 reported in bulk materials. At H=60 kOe the maximum magnetoresistance {Delta}{rho}/{rho}{approx}0.95. No discernible hysteresis, as might be expected for structural phase transitions, was observed. When plotted as a function of reduced temperature T/T{sub c}, the magnetization extrapolated to zero H is best fit by a Brillouin function with an effective spin value {l_angle}S{r_angle} much larger than the {l_angle}S{r_angle}=1.9 indicated by the composition. This may be indicative of magnetic polaron formation, especially near the magnetic and transport transition temperatures. At temperatures far below T{sub c} there is an increase in resistivity of the thin films, which is considerably modified by the application of a field of 50 kOe. The conductivity, however, remains finite as the temperature approaches zero, indicating transport in states close to but above the mobility edge. {copyright} {ital 1997 American Institute of Physics.}},
doi = {10.1063/1.365014},
url = {https://www.osti.gov/biblio/496540}, journal = {Journal of Applied Physics},
number = 8,
volume = 81,
place = {United States},
year = {1997},
month = {4}
}