Role of spin-glass phase for magnetoresistance enhancement in nickel substituted lanthanum calcium manganite
IR@NPL: CSIR-National Physical Laboratory, New Delhi
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| Title |
Role of spin-glass phase for magnetoresistance enhancement in nickel substituted lanthanum calcium manganite
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| Creator |
Yadav, Akash
Shah, Jyoti Gupta, Rekha Shukla, Ajay Singh, Sukhvir Kotnala, R. K. |
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| Subject |
Materials Science
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| Description |
Effect of Ni substitution in lanthanum calcium manganite (LCMO) has been investigated for change in magnetoresistance (MR). Scanning electron microscopy images revealed decrease in grain size from 3.72 mu m to 0.55 mu m by Ni substitution. Maximum increase in MR has been found 28% at low temperature (100 K) for x=0.10, Ni substitution at Mn site. Metal insulator transition temperature has been decreased from 253.2 K for x=0.0-90 K for x=0.10. Above x=0.10, Ni substitution no metal-insulator transition temperature appeared due to the presence of porosity in the samples. Ni substitution lowered the magnetic transition temperature from 255 K for x=0.0-125 K for x=0.25. Lowering of irreversible temperature (TA from 250 K for x=0.0-135.4 K for x=0.20 has been obtained by zero field cooled (ZFC) and field cooled (FC) measurements confirm reduction of ferromagnetic clusters and spin-glass phase like behavior due to Ni presence. The spin-glass phase presence allows spin-polarized tunneling even at low magnetic field, which ultimately results in enhancement of MR at low temperature. Core level X-ray photoelectron spectroscopy measurements confirm Ni2+ charge state of Ni ions and increase in Mn4+/Mn3+ ratio with increasing Ni content. Increase in resistivity and weakening of ferromagnetism with Ni substitution at Mn site has been observed due to the reduction in grain size and dilution of double exchange interaction.
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| Publisher |
Elsevier
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| Date |
2016-08-15
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://npl.csircentral.net/2348/1/Role%20of.pdf
Yadav, Akash and Shah, Jyoti and Gupta, Rekha and Shukla, Ajay and Singh, Sukhvir and Kotnala, R. K. (2016) Role of spin-glass phase for magnetoresistance enhancement in nickel substituted lanthanum calcium manganite. Ceramics International, 42 (11). 12630 -12638. ISSN 0272-8842 |
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| Relation |
http://npl.csircentral.net/2348/
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