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Title: | Study of low field magneto-resistance in La0.67A0.33MnO3 [A ≡ Ca, Ba, Sr] screen printed films |
Authors: | Khare, Neeraj Moharil, U P Singh, B Gupta, A K |
Keywords: | Magneto-resistance;Polycrystalline films;Epitaxial films;Laser ablation technique;spin Polarized tunneling |
Issue Date: | Jan-2004 |
Publisher: | CSIR |
Abstract: | Screen printed polycrystalline films of La0.67A0.33MnO3 [A ≡ Ca, Ba, Sr] have been found to exhibit substantially large magneto-resistance at low fields and low temperature as compared to an epitaxial La0.67Ba0.33MnO3 film prepared by laser ablation technique. A value of magneto-resistance ratio (MRR) of 6 % has been achieved even at a dc field of 600 Oe at 77 K. Temperature dependence of MRR of the screen-printed films show that MRR increases with decrease of the temperature. This MRR-T behaviour shows that magneto-resistance in screen printed films has its origin in grain boundaries. The variation of MRR of these films with magnetic field at 77 K shows sharp increase in the field 0-1 kOe and slower increase for the field 1-3 kOe. Sharp increase in the MRR has been attributed to spin polarized tunnelling occurring across the grain boundaries, where as the slower increase in MRR for a field variation of 1-3 kOe is due to suppression of spin disorders present in the grain boundary region in the polycrystalline films. |
Page(s): | 62-66 |
URI: | http://hdl.handle.net/123456789/9568 |
ISSN: | 0975-1041 (Online); 0019-5596 (Print) |
Appears in Collections: | IJPAP Vol.42(01) [January 2004] |
Files in This Item:
File | Description | Size | Format | |
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IJPAP 42(1) 62-66.pdf | 760.38 kB | Adobe PDF | View/Open |
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