Low field magnetic interactions in the transition metals doped CuS quantum dots.

[Display omitted] • Successful synthesis of PVP capped doped CuS quantum dots. • A marked increase in the band gap of the quantum dots. • Low field magnetic interactions at room temperature. Polyvinlypyrrolidone (PVP) capped and magnetic transition metals (TM = Fe, Co and Cr) doped CuS quantum dots (Cu 1- x TM x S; x = 0.02 & 0.04) were synthesized by low entropy facile chemical co-precipitation method. The structural, optical and magnetic characterizations of the synthesized QDs were done by using X-ray diffraction (XRD) technique, UV–Vis-NIR absorption spectroscopy, photoluminescence (PL) spectroscopy and superconducting quantum interference device (SQUID) respectively. The low field non-linearity and the presence of coercivity in the M−H loops indicate the presence low field magnetic (spin–spin) interactions between the doped cations. [ABSTRACT FROM AUTHOR]