The Electronic and Magnetic Properties of FCC Iron Clusters in FCC 4D Metals

Abstract

The electronic and magnetic structures of small FCC iron clusters in FCC Rh, Pd and Ag were calculated using the discrete variational method as a function of cluster size and lattice relaxation. It was found that unrelaxed iron clusters, remain ferromagnetic as the cluster sizes increase, while for relaxed clusters antiferromagnetism develops as the size increases depending on the host metal. For iron in Rh the magnetic structure changes from ferromagnetic to antiferromagnetic for clusters as small as 13 Fe atoms, whereas for Fe in Ag antiferromagnetism is exhibited for clusters of 24 Fe atoms. On the hand, for Fe in Pd the transition from ferromagnetism to antiferromagnetism occurs for clusters as large as 42 Fe atoms. The difference in the magnetic trends of these Fe clusters is related to the electronic properties of the underlying metallic matrix. The local d densities of states, the magnetic moments and hyperfine parameters are calculated in the ferromagnetic and the antiferromagnetic regions. In addition, the average local moment in iron-palladium alloys is calculated and compared to experimental results.Key words magnetic moment · hyperfine fine field · isomer shift · density of states · impurity · cluster · 4d host · iron.

Thermal plasma processed ferro-magnetically ordered face-centered cubic iron at room temperature

“…Iron is known to possess ferromagnetism at room temperature in its bcc phase and get transformed into paramagnetic fcc phase above 913 C. Again at the temperatures above 1337 C, it transforms into the paramagnetic bcc phase and remains so up to its melting temperature. [11][12][13] In most of the investigations, [14][15][16][17][18][19][20][21][22][23] the presence of two stable magnetic states of fcc iron have been pointed out: low spin (LS) and high spin (HS). However, contrary views, based on the theoretical calculations as well as experimental observations have been expressed on the types of magnetic structures corresponding to these states.…”