Tailoring the Structure and Properties of Epitaxial Europium Tellurides on Si(100) through Substrate Temperature Control

In this study, we improved the growth procedure of EuTe and realized the epitaxial growth of EuTe(4). Our research demonstrated a selective growth of both EuTe and EuTe(4) on Si(100) substrates using the molecular beam epitaxy (MBE) technique and reveals that the substrate temperature plays a crucial role in determining the structural phase of the grown films: EuTe can be obtained at a substrate temperature of 220 °C while lowering down the temperature to 205 °C leads to the formation of EuTe(4). A comparative analysis of the transmittance spectra of these two films manifested that EuTe is a semiconductor, whereas EuTe(4) exhibits charge density wave (CDW) behavior at room temperature. The magnetic measurements displayed the antiferromagnetic nature in EuTe and EuTe(4), with Néel temperatures of 10.5 and 7.1 K, respectively. Our findings highlight the potential for controllable growth of EuTe and EuTe(4) thin films, providing a platform for further exploration of magnetism and CDW phenomena in rare earth tellurides.