Magnetic properties of RCo4M (R=Y, Nd and Ho; M=B, Al and Ga)

Abstract

Magnetic and crystallographic measurements have been made for the compounds RCo4M (R = Y, Nd, and Ho; M = B, Al, and Ga) to intercompare the magnetic properties of RCOJB, RCoaM (M = Al and Ga) and RCo5. The compounds RCo4B crystallize in the CeCo,B type structure, while RCo4M (M = Al and Ga) in the CaCuS type. The following main conclusions have been obtained: ( 1) the Curie temperature and the averaged Co-moment of RCo,M (R = Y, Nd, and Ho; M = B, Al, and Ga) are lower and smaller than those of RCo5, respectively, and 6i-site Co-moment in RCo$ is smaller than the 2csite Co-moment by the influence of the neighboring B-layer; (2) magnetocrystalline anisotropy of R-sublattice of RCo4B is stronger than that of RCo,, while that of RCo4A1 is remarkably weaker than that of RCo,; (3) the Co-sublattice anisotropy constants of YCo&I (M = B and Al) are 20% or less of that of YCo,; and (4) JR-o0 and Jco-cO, which are the exchange parameters of the atomic pairs in NdCo,+M (M = B and Al), have been estimated to be JR.&k N 7 K and Jc,.co/k N 200 K, where k is the Boltzman constant. 5551

The influence of substituting Si for Co on the magnetic properties of PrCo5

“…These properties are resulting from the combination of the 3-d itinerant magnetism of the Co sublattice and the 4f localized magnetism of the R sublattice. Numerous attempts have been made to improve the overall properties of these materials by substituting various elements for R or Co [1][2][3][4]. Here, we present a fundamental investigation of the effect of substituting Si for Co on the intrinsic magnetic properties of the PrCo 5 phase.…”

Magnetic phase diagrams of R3(Co:Ni)13B2, R=Y and Nd intermetallic compounds

“…In contrast to the 1:5 and 3:13:2 series, the case of 1:4:1 is peculiar. While YCo 4 B undergoes a SRT [20] NdCo 4 B remains axial at all temperatures [30]. In this case the temperature dependence of the Co anisotropies, due to the different Co site anisotropies, plays the main role in the SRT.…”

The influence of mechanical alloying on the magnetic properties of U−Co−B system

“…Magnetic moments (on both the R and cobalt sites) are aligned along the c direction [2]. Within the last few year's the physical properties of UCo4B, crystallizing in the hexagonal CeCo4B-structure, have been investigated in detail.…”