Paramagnetic and anti-ferromagnetic interactions in sol–gel derived Zn_1−xMn_xO [50 MeV Li³⁺ irradiated (x=0.04) and unirradiated (x=0.02 and 0.04)] samples

Abstract

A study of Zn_1−x Mn _x O (x=0.02 and 0.04) pellets synthesized by sol–gel technique was performed to explore the inherent magnetic interactions. 50 MeV Li³⁺ ion beam irradiation was employed to a Zn_0.96Mn_0.04O pellet. Structural, morphological, compositional and magnetic properties of the samples were investigated. The single-phase structural nature was destroyed for a 4 at% Mn-doped sample with the formation instead of a new phase of ZnMnO₃, as observed from the X-ray diffraction (XRD) pattern. The intensity of the multiphase component decreases with the ion irradiation. XRD also indicates that Mn incorporation in ZnO increased with increasing doping and, interestingly, with irradiation. The tendency of grain size is the opposite. The magnetic measurements of the samples indicate anti-ferromagnetic interactions coupled with paramagnetic counterparts. The study clearly exhibits the modification of magnetic properties with Li³⁺ ion beam irradiation. It has been interpreted that structural and compositional quality up-gradation with irradiation is responsible for such changes in magnetic behavior.

Keywords:

• ion irradiation
• magnetic property
• structure and composition

Acknowledgements

This work was financially supported by DST, Government of India, and IUAC, New Delhi, vide project nos.: SR/FTP/PS-31/2006 and UFUP-43308, respectively. The authors S.K.N. and R.K. are thankful to UGC and CRNN-C.U., respectively, for providing them fellowships. We acknowledge UGC-DAE CSR, Indore, and IUAC, New Delhi, to use their magnetic measurement and pelletron facility.