Magnetic Nanostructures of Europium Telluride

Abstract

Nanostructured magnetic materials have attracted considerable attention due to the wide range of novel properties and their potential application in optoelectronic and spin-transport-based (spintronic) devices. The antiferromagnetic semiconductor EuTe is considered a classical Heisenberg magnet with strongly localized magnetic moments. EuTe is a candidate material for prototype spintronic devices and combined with IV-VI semiconductors has applications in the construction of lasers and detectors in the infrared region. Recently, interesting magnetic phenomena have been observed in EuTe based heterostructures. The purpose of this project is to study the influence of size reduction down to nanometer scale in the magnetic properties of EuTe. Bi-dimensional multilayer systems of EuTe and IV-VI semiconductors and zero-dimensional EuTe quantum dots on IV-VI semiconductors or directly on BaF2 will be studied. The samples will be grown by molecular beam epitaxy using the MBE system at LAS/INPE, and structurally characterized by atomic force microscopy and x-ray techniques. SQUID magnetic characterization will be made at the Physics Institute of São Paulo University (IFUSP) in cooperation with Prof. Valmir Chitta, while magnetic ressonant x-ray diffraction is planned at the XRD2 line of the Brazilian Synchrotron Laboratory. The optical characterization, in cooperation with Prof. André B. Henriques from IFUSP, will include absorption, luminescence and Faraday rotation measurements. This project is included into the thematic of FAPESP No 2007/50968-0 project, entitled "Research on novel materials involving intense magnetic fields and low temperatures" and coordinated by Prof. Nei F. de Oliveira Jr. from IFUSP.