Plonųjų La1-xSrxMnO3 sluoksnių struktūros įtaka jų magnetovaržai

Abstract

Ištirta plonųjų La1-xSrxMnO3 sluoksnių, užaugintų ant polikoro padėklo, legiravimo laipsnio x, maksimalios varžos temperatūros ir kristalitų dydžio įtaka šių sluoksnių magnetovaržai (MR). Nustatyta, kad užauginus sluoksnius su x=0,17, išlaikant padėklo temperatūrą 750 °C, galima sukurti magnetinio lauko jutiklius, matuojančius kambario temperaturoje magnetinės indukcijos vertę neatsižvelgiant į magnetinio lauko kryptį.

Magnetoresistance of thin polycrystalline La1-xSrxMnO3 films deposited on lucalox substrate using MOCVD technique was investigated in pulsed magnetic fields up to 12 T. The results demonstrate high influence of film fabrication technology on the electrical transport characteristics and magnetoresistance of the films. Decrease of composition x from 0.3 down to 0.17, has resulted in magnetoresistance increase from 28 % up to 34 % at 9 T. For the films with x= 0.17 magnetoresistance anisotropy was less than 10 %. For films with this composition a decrease of substrate temperature (from 750 to 650 °C) which is kept constant during to growth determined a decrease of crystallite dimensions from 170 nm to 110 nm. Such conditions resulted in decrease of magnetoresistance from 34 % to 23 % at 9 T. It is concluded that La0,83Sr0,17MnO3, films grown at 750 °C temperature could be used for design of magnetic field sensors which are able to measure magnetic field induction in small volumes independently from magnetic field direction with respect to the sensor's orientation.