Yttrium Orthoferrite Powder Obtained by the Mechanochemical Synthesis

Yttrium orthoferrite (YFeO3) powder was prepared by a mechanochemical synthesis from a mixture of Y2O3 and alpha-Fe2O3 powders in a planetary ball mill for 2.5 h. The obtained YFeO3 powder sample was characterized by X-ray diffraction (XRD), Raman and infrared spectroscopy. The average crystallite size calculated by the Scherrer equation was 12 nm. The Mossbauer spectroscopy at room temperature confirms the superparamagnetic character of YFeO3 orthoferrite sample

Magnetic field influence on optical properties of Cd1-xMnxS (x=0; 0.3) quantum dots: Photoluminescence study

We have synthesized CdS and Cd0.7Mn0.3S nanocrystals with diameters of about 4.5 nm. These materials have been studied using photoluminescence spectroscopy with various excitation energies in the temperature range from 1.8 to 300 K, in magnetic field up to 5T. We registered surface and defect states as well as two Mn2+ energy levels that correspond to Mn2+ ions in two different crystal environments. We proposed the scheme of energy levels and transitions that explain obtained experimental results. (C) 2012 Elsevier B. V. All rights reserved