Magnetic Properties of Rare Earth Ions in Garnets

Abstract

Abstract : Susceptibility measurements in the range 20 to 1.5 K are reported for the 8 paramagnetic garnets with the composition R3X5O12, where R equals Gd(3+), Tb(3+), Ho(3+) or Tm(3+) and X equals Al(3+) or Ga(3+) together with microwave resonance determinations of the principal g-values of the ions Nd(3+), Dy(3+), Er(3+) and Yb(3+) substituted into diamagnetic Lu3Al5O12 and Lu3Ga5O12. Results are interpreted qualitatively as indicating highly anisotropic and relatively large local crystalline electric fields, and the effect of these on the properties of ferrimagnetic rare earth iron garnets is concerned. In the ferrimagnetic garnets, the rare earth ions will almost always divide into 6 non-collinear sublattices, whose magnetic moments make quite large angles with the 2 antiparallel Fe sublattices. For YbIG, it was possibl o make a numerical estimate of the angles of canting. (Author)