Structural Phase Transitions in Al-Rich C-Doped Mnal Thin Films

Abstract

We study the crystal structure of carbon-doped Al-rich MnAl thin films deposited on Si substrates. The effects of carbon content and vacuum heat treatment parameters are studied. It is shown that the carbon content, in combination to heat treatment, allows to tailor structural phase transitions in the films. The main phases detected are Al2Mn3, pure Mn, and pure C. As carbon content increases, the amount of Al2Mn3 phase decreases and the content of pure crystallized Mn phase increases. In addition, it is shown that as the heat treatment temperature increases – up to 500 °C – the Al2Mn3 phase content increases, whereas a pure C phase appears at lower temperatures.