Computational search for novel magnetic clusters with large magnetic anisotropy energy
The clusters of transition metal atoms often show high spin moments but generally are reactive with the environment. Passivation of the surface atoms can lead to more stable clusters. We have explored one such avenue for passivation in this work. We picked the As@Ni12@As20 cluster which in the neutral state has a magnetic moment of 3 μB. We doped this cluster with various numbers of Mn atoms by substituting Ni atoms. The substitutional doping leads to spin moments located on the Mn atoms. The doping leads to symmetry breaking and as a consequence the number of structural isomers and spin ordered states for each isomer becomes very large. We have investigated all possible ferromagnetic Mn doped clusters for a given number of dopants. Subsequently all the possible anti-ferromagnetic states for the lowest energy structure were examined. The results show that the encapsulation within the As20 cage stabilizes the clusters and the atomization energy of the clusters increases as the number of dopant increases. These clusters have small energy barrier for reversal of magnetization and also have rich configuration space with many low-lying spin states.^
Hoque, Nabil Md Rakinul, "Computational search for novel magnetic clusters with large magnetic anisotropy energy" (2015). ETD Collection for University of Texas, El Paso. AAI1600321.