Polarized Temperature Dependent Raman Study of Bi2Te3-Cr2Ge2Te6 heterostructure and the Ferromagnetic Insulator Cr2Ge2Te6

• Published in: arXiv.org
• Main Authors: Yao Tian, Ji, Huiwen, R J Cava L D Alegria, Petta, J R, Burch, Kenneth S
• Format: Paper
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 07.10.2014
• Subjects: Anharmonicity; Bismuth tellurides; Electrons; Ferromagnetic materials; Heterostructures; Phonons; Quantum Hall effect; Substrates; Temperature dependence; Topological insulators; Topology

Cr2Ge2Te6 has been of interest for decades, as it is one of only a few ferromagnetic insulators. Recently, this material has been revisited due to its potential as a substrate for Bi2Te3, a topological insulator. This enables the possibility of studying the anomalous quantum Hall effect in topological insulators, and a route to novel spintronic devices. To probe the compatibility of these two materials, we use polarized variable temperature Raman microscopy to study Bi2Te3-Cr2Ge2Te6 heterostructure as well as the phonon dynamics of Cr2Ge2Te6. We found the temperature dependence of the Cr2Ge2Te6 phonons results primarily from anharmonicity, though a small magneto-elastic coupling is also observed. Our results confirm the potential of Cr2Ge2Te6 as a substrate for topological insulators.