LAUSR

Three different contributing mechanisms were considered to calculate the magnetisation (M) of p-type Pb1−xMnxSe and n-type Pb1−xMnxS. The first mechanism comes from the valence band diamagnetism which is calculated in the frame of a two-band model; the second mechanism which we consider arises from the spin densities of holes and electrons and we use a six-level k⃗.π⃗ theory in the second-order perturbation theory in the effective mass representation. The third mechanism is the impurity Mn+2 ion contribution, and we consider small clusters consisting of one, two and three spins to evaluate it. The three spin clusters include both open and closed types and it was observed that the former two mechanisms contribute very little to the magnetisation compared to the latter. However, their importance cannot be ignored because they provide a deeper understanding of the underlying physical mechanisms involved in carrier spin polarisation and orbital diamagnetism of the host matrix in which the Mn+2 spins are embedded. Good agreement between our theory and the experiment is another interesting and distinct feature of this work.