Nickel doped zinc selenide nanoparticles for spin based dilute magnetic semiconductor applications

Abstract

For spin based applications, Zn1-xNixSe nanoparticles were synthesised by co-precipitation method at room temperature with various compositions (x = 0.03, 0.05, 0.07, 0.09, 0.1, 0.15, 0.2). Structural and morphological studies of the least explored Zn1-xNixSe nanoparticles have been accomplished with the help of X-ray diffractometer (XRD), Field Emission Scanning Electron (FESEM) and Transmission-Electron Microscopy (TEM) measurement. The nano-crystallite size is obtained in range 11–18 nm with cubic phase of Zn1-xNixSe. Morphological study indicates formation of nanospheres and occurrence of some agglomeration in nanoparticles. Thermogravimetric (TG/DTA) analysis shows the two step degradation process in as prepared undoped ZnSe and Ni doped ZnSe nanoparticles. UV–visible spectroscopy is employed for optical analysis and energy band gap of Ni doped ZnSe nanomaterials is found in range greater than bulk ZnSe (2.8 eV). Fourier Transfom Infrared (FTIR) study confirmed doping of Ni ions in ZnSe nanoparticles. Magnetic properties of Ni-doped ZnSe nanoparticles are investigated using vibrating-sample magnetometer (VSM) at 300 K and electron spin resonance (ESR) spectra and analysis confirms Ni induced ferromagnetism tuning in the prepared samples. Induced ferromagnetic ordering indicates that Ni spins in the doped Zn1-xNixSe can be successfully tuned for static-spins and spin dynamics applications.