Impact of Li 3+ ion irradiation on magnetic properties of Mn doped ZnO: correlation with defects and structural property

Present work aims to study the impact of 50 MeV Li 3+ ion irradiation on magnetic properties and their correlation with the substitutional incorporation of Mn at Zn site (Mn Zn ) and defects in Mn:ZnO (Mn doped ZnO). 2 at% Mn:ZnO has been synthesized by solid-state reaction method and irradiated with fluences 10 12 , 10 13 and 10 14 ions/cm 2 . The concomitant changes have been probed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and magnetization measurements. XRD patterns indicate single-phase nature of the samples and Mn Zn nicely varied with fluence of irradiation. Temperature dependent dc and ac magnetization (M-T) measurement reveals a minor presence of spin glass nature or superparamagnetism (SPM) though all of the samples are strongly intrinsically ferromagnetic and field dependent magnetization (M-H) measurement actually confirms this observation. It is noteworthy to observe that the ordering of spins and the magnetic parameters viz. saturation magnetization (M S ), remnant magnetization (M R ) and coercivity (H C ) can be tuned by fluences of irradiation. Finally, proportion of defect [particularly zinc vacancy (V Zn )] and Mn Zn seems to dictate the trend of variation of magnetization (M S and M R ). Temperature dependent ac magnetization measurement and magnetic relaxation measurement actually detect a weak spin glass nature of the samples and eliminate the possibility of SPM.