Luminescence and high temperature ferromagnetism in YAlO nanophosphors: Materials for efficient next generation LEDs and spintronic applications

Abstract

Current research on environment friendly and efficient luminescent materials for white LEDs, envisaged as next generation energy efficient lighting devices, has spurred research into the different forms of yttrium-aluminum-oxide (YAlO) (YAG: garnet structured YAlO and YAM: monoclinic structured YAlO), including the discovery of a new phase of tetragonal structured YAlO named YAT. Appropriate luminescence in the visible-yellow region has been realized by doping rare earth (Ce) in the YAlO host. Interestingly, this work indicates that all the studied YAlO nanophosphors (NPs) exhibit dilute ferromagnetism up to 600 K. The observed magnetic character of YAlO NPs is attributed to the oxygen vacancies and remains unperturbed even after Ce doping, thereby establishing the independent nature of the two phenomena. This non-interfering luminescence and magnetic character of the YAlO NPs is anticipated to have a wide application potential in high temperature spintronics, LEDs and other biological applications.