Structural and magnetic properties of antiperovskite Mn3NiNx thin films

Influence of nitrogen fractions[N-f=N-2/(N-2+Ar-2)] on the structural and magnetic properties of Mn3NiNx thin films prepared on quartz substrates using magnetron sputtering have been studied. The N/Ni ratio increased (N/Ni=0.3-1.1) while the peak (200) shifted to lower angles with increasing N-f. It revealed that there was significant variation in the preferred orientation and Neel temperature (T-N) for the films with increasing N-f. Strong indication for a frozen state is found, determined from the difference between field-cooled and zero-field-cooled magnetizations. The ac susceptibility measurements show a peak position shifting as a function of the driving frequencyf and magnetization value does not saturate in the field range. These findings consistently demonstrate that Mn3NiNx thin films exhibit a spin-glass state at low temperature. (C) 2015 Elsevier B.V. All rights reserved.