Magnetic Clusters in the (CuInSe 2 ) 1 − x (TaSe) x Alloy System (0 < x ≤ 0 . 5)

Polycrystalline samples of (CuInSe 2 ) 1 − x (TaSe) x system were prepared by the melt and anneal technique in the composition range 0 < x ≤ 0 . 5. It was found that the solubility of TaSe in the CuInSe 2 ternary matrix is around 10 %; however, up to x = 0 . 5 are composed by a mean tetragonal CuInSe 2 -like phase with traces of the TaIn 0 . 67 Se 2 phase. A preliminary T-x phase diagram is presented. To determinate the induced magnetic behavior, DC magnetic susceptibility measurements as a function of temperature, using the Zero Field Cooling-Field Cooling (ZFC-FC) protocol, were performed in samples with compositions x = 0 . 05 and 0 . 5. It was found that the magnetic behavior evolves from diamagnetic (CuInSe 2 , x = 0) to paramagnetic ( x = 0 . 05) to weak ferromagnetic ( x = 0 . 5). The observed hysteresis between FC and ZFC curves, for x = 0 . 05 and x = 0 . 5 suggest the presence of magnetic clusters; fitting FC curves with Langevin function it was found that clusters are composed for approximately 10 3 Ta-atoms. of single-peak profile fitting carried out through the Bruker DIFFRAC plus software. Each reflection was modeled by means of a pseudo-Voigt function.