Swift heavy ion irradiation induced modifications in magnetic and dielectric properties of Mn–Ca ferrite
| Autor: | M. S. Dhawan, M. Alzamora, E. Saitovitach, Y.T. Xing, S. N. Dolia, Arun S. Prasad, P. K. Sharma, K. Asokan, R.K. Singhal, S. P. Pareek, Arvind Samariya, Sudhish Kumar |
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| Rok vydání: | 2012 |
| Předmět: |
Materials science
Analytical chemistry General Physics and Astronomy Surfaces and Interfaces General Chemistry Dielectric Coercivity Condensed Matter Physics Nanocrystalline material Surfaces Coatings and Films Condensed Matter::Materials Science Magnetization Swift heavy ion Nuclear magnetic resonance Ferrite (magnet) Irradiation Superparamagnetism |
| Zdroj: | Applied Surface Science. 258:4207-4211 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/j.apsusc.2011.06.011 |
| Popis: | The effects of 200 MeV Ag 15+ ion irradiation on structural, magnetic and dielectric properties of nanocrystalline Mn–Ca ferrite have been investigated. The specimens characterized using XRD confirmed the formation of cubic spinel structure. The TEM images revealed the spherical morphology consistent with the crystalline diameter. After irradiation by 200 MeV Ag ions, saturation magnetization, coercivity, and blocking temperature were enhanced appreciably which could be attributed to swift heavy ion (SHI) irradiation induced modifications in surface states of the nanoparticles, slight increase in crystallite size and cationic re-distribution. The dielectric measurements revealed that both dielectric constant ( ɛ r ) and the loss tangent (tan δ ) disperse normally as a function of frequency of the externally applied electric field. The increase in ɛ r and tan δ on irradiation could be attributed to the surface modifications through slight crystal growth and hence the availability of sufficient number of Fe 2+ /Mn 3+ ions particularly at the octahedral site on grain boundaries showing a fair agreement with the magnetization results. |
| Databáze: | OpenAIRE |
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