Local Electronic Structure Of Heavy-ion Irradiated Nano-crystalline Stoichiometric La0.8Sr0.2Mn0.8Fe0.2O3 Particles Using Highresolution Mössbauer Spectroscopy
Usha Chandra, K. Asokan, V. Ganesan
Volume 4, Issue 11, Page 862-868 | DOI: 10.5185/amlett.2013.4455
Mössbauer spectroscopy; swift heavy ions irradiation; X-ray diffraction; ferromagnetic coupling; Magnetization; nanocrystalline; vacancy-doped manganites; perovskites.
Nanocrystalline stoichiometric La0.8Sr0.2Mn0.8Fe0.2O3 manganites synthesized by sol gel technique were irradiated by 200 MeV Ag+16 ion beam at various fluences and investigated by X-ray diffraction (XRD), magnetization and high resolution Mössbauer spectroscopic techniques. The analysis of Mössbauer patterns were done using Kopcewicz et al. (2004) proposition considering Double exchange mechanism. Both XRD and Mössbauer spectroscopic analysis indicated isostructural vacancy formation at Mn site at the fluence 5x1012 ions/cm2. The system showed amorphous phase at the higher fluence of 1x1013ions/cm2. The local electronic environments seen through high resolution Mössbauer spectroscopic technique on the irradiated systems were understood in terms of ferromagnetic coupling between different Mn environment surrounding Fe ions. This proposition is supported by enhanced magnetization observed in the irradiated samples (Kopcewicz et al., 2004). The similarity to the hydrostatic applied pressure (at low value) is seen through the transformation from Fe4+ to Fe3+ at low fluence. Copyright © 2013 VBRI press.