Effects of dopant ion and Mn valence state in the La{sub 1-x}A{sub x}MnO{sub 3} (A=Sr,Ba) colossal magnetoresistance films

Journal Article · Fri Jan 15 04:00:00 EST 2010 · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films

DOI:https://doi.org/10.1116/1.3256197· OSTI ID:22053598

Choi, Sun Gyu; Wang, Seok-Joo; Park, Hyung-Ho; Hong, MunPyo; Kwon, Kwang-Ho ^[1]

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1. Department of Materials Science and Engineering, Yonsei University, 134 Sinchon-dong, Seodaemun-ku, Seoul 120-749 (Korea, Republic of)

The structural and electrical properties of Mn-based colossal magnetoresistance (CMR) thin films with controlled tolerance factor and Mn ion valance ratio were studied using crystal structure and chemical bonding character analyses. La{sub 0.7}Sr{sub 0.3}MnO{sub 3}, La{sub 0.7}Ba{sub 0.3}MnO{sub 3}, and La{sub 0.82}Ba{sub 0.18}MnO{sub 3} thin films with different contents of divalent cations and Mn{sup 3+}/Mn{sup 4+} ratios were deposited on amorphous SiO{sub 2}/Si substrate by rf magnetron sputtering at a substrate temperature of 350 deg. C. The films showed the same crystalline structure as the pseudocubic structure. The change in the sheet resistance of films was analyzed according to strain state of the unit cell, chemical bonding character of Mn-O, and Mn{sup 3+}/Mn{sup 4+} ratio controlling the Mn{sup 3+}-O{sup 2-}-Mn{sup 4+} conducting path. Mn L-edge x-ray absorption spectra revealed that the Mn{sup 3+}/Mn{sup 4+} ratio changed according to different compositions of Sr or Ba and the Mn 2p core level x-ray photoelectron spectra showed that the Mn 2p binding energy was affected by the covalence of the Mn-O bond and Mn{sup 3+}/Mn{sup 4+} ratio. In addition, O K-edge x-ray absorption spectra showed covalently mixed Mn 3d and O 2p states and matched well with the resistivity changes of CMR films. Temperature coefficient of resistance values were obtained at approximately -2.16%/K to -2.46%/K of the CMR films and were correct for infrared sensor applications.

• OSTI ID: 22053598
• Journal Information: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Journal Name: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films Journal Issue: 1 Vol. 28; ISSN 1553-1813
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BINDING ENERGY
CATIONS
CHEMICAL BONDS
CRYSTAL STRUCTURE
LANTHANUM COMPOUNDS
MAGNETORESISTANCE
MAGNETRONS
MANGANESE IONS
MANGANESE OXIDES
OXYGEN IONS
SENSORS
SILICON OXIDES
SPUTTERING
SUBSTRATES
SURFACE COATING
THIN FILMS
X-RAY PHOTOELECTRON SPECTROSCOPY
X-RAY SPECTRA