Single Crystal Measurements of Anisotropy Constants of R₂Fe₁₄B (R=Y, Ce, Pr, Nd, Gd, Tb, Dy and Ho)

The first order anisotropy constants K u1 of the recently found tetragonal rare earth-iron borides R 2 Fe 14 B (P4 2 /mnm) have been measured for R=Y, Ce, Pr, Nd, Gd, Tb, Dy and Ho in a magnetic field up to 1600 kA/m from 4.2 K to about 600 K on single crystal samples.