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
- MARTECH, the Florida State University, Tallahassee, Florida 32306-4000 (United States)
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.}
- OSTI ID:
- 496540
- Report Number(s):
- CONF-961141-; ISSN 0021-8979; TRN: 97:016233
- Journal Information:
- Journal of Applied Physics, Vol. 81, 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
Similar Records
Dopant and temperature induced structural phase transitions in La{sub {bold 2{minus}}}{ital x}Sr{sub {ital x}}CuO{sub {bold 4}}
Electrical properties of La{sub 0.7{minus}x}Pr{sub x}Sr{sub 0.3}MnO{sub 3} perovskite