Title :
Annealing effect on magnetic characteristics on (La,Sr)MnO3 sputtered films
Author :
Namikawa, Tatsuo ; Kaneta, Kumiko ; Matsushita, Nobuhiro ; Nakagawa, Shigeki ; Naoe, Masahiko
Author_Institution :
Dept. of Phys. Electron., Tokyo Inst. of Technol., Japan
fDate :
9/1/1999 12:00:00 AM
Abstract :
A perovskite type of (La,Sr)MnO3 films were deposited on SiO2/Si substrates with amorphous surface by using the facing targets sputtering apparatus. Although the film as-deposited at P(O2) of 0.3 mTorr was not fully crystallized and the MR ratio was as small as 0.03% at the applied field of 5 kOe, it increased up to 2.5% for the film post-annealed at 850°C in air for 10 min. The partial O2 pressure P(O2) strongly affected their crystallinity as well as the Mn content CMn. The film as deposited at P(O2) of 0.03 mTorr was composed of crystallites with excellent (100) orientation at relatively low substrate temperature Ts up to 500°C and the large MR ratio of 3.8% was attained even at room-temperature measurement. Since this MR response exhibits excellent linearity, these LSMO films seem to be applied for magnetic sensor devices. It is clarified that the annealing process in preparation of LSMO film effectively increases the MR ratio of the film with insufficient crystallinity, and is not effective for the fully crystallized film
Keywords :
annealing; colossal magnetoresistance; lanthanum compounds; magnetic hysteresis; magnetic thin films; sputter deposition; strontium compounds; LaSrMnO3; Mn content; Si; SiO2; annealing; crystallinity; facing targets sputtering; magnetic sensor devices; magnetoresistance; partial O2 pressure; perovskite; sputtered films; substrate temperature; Amorphous magnetic materials; Amorphous materials; Annealing; Crystallization; Linearity; Magnetic films; Semiconductor films; Sputtering; Substrates; Temperature sensors;
Journal_Title :
Magnetics, IEEE Transactions on
