Perturbation of exchange interaction in Nd–Ni spin subsystem of nickelate

A spin subsystem of a nano-sized NdNi 8 of a nickelate superconductor is chosen to calculate its contribution in controlling magnetic phase transition. The role of the spin distribution of NdNi 8 in controlling magnetization ( M ) is studied within the framework of the mean field theory (MFT). Two different levels of perturbation in the exchange interaction between spins of Ni and Nd have been used. M ( H , T ) has been calculated numerically for perturbations of 0, 0.15 and 0.30 with respect to an unperturbed J 0 . Changes in M ( H ) in the range of T = 10.0–300.0 K have been found to be very sensitive to perturbation. Possibility of a magnetic phase transition has been found which is sensitive to the perturbation of the exchange integral. Sensitivity of the broadening of the phase transition is weaker for the level of perturbation in comparison with that for the magnetic field. Susceptibility is also calculated and analysed to understand how perturbed exchange integral affects magnetic phase transition in spin distribution of NdNi 8 .