First-principles investigations of chirality in trimetallic alloy clusters: AlMnAun (n = 1-7)

Chirality, also called handedness, plays a crucial role in function ranging from biological self-assembly schemes, organic polymer functionalities, to optical material designs. In this Article, we demonstrated a first-principles investigation of chirality in magnetic AlMnAun(0/+1/-1) (n = 1-7) clusters. Optimized structures of the AlMnAun clusters exhibit configurational combinations between AlAun+1 and MnAun+1 clusters, indicating a subtle but equal competition between Au-Al and Au-Mn interactions in the alloy clusters. High magnetic moments are equal to or greater than 4μB in AlMnAun clusters due to the presence of the Mn dopant. Chirality turns up with the forms of right-handed and left-handed in stable AlMnAu5, AlMnAu6, and AlMnAu7 clusters. As a result, reflection symmetries are found in vibrational Raman and circular dichroism spectra of these chiral pairs. The present study shows that chiral magnetic clusters can be composed by doping two heteroatoms with one intrinsic magnetic dopant into small gold clusters.