Pseudobinary Series Research Articles

Electric field gradient in cubic intermetallic europium compounds with unstable europium valence

Spin echo NMR measurements in EuPd 2 and EuPt 2 are reported. The europium hyperfine fields were determined and found to be equal to B hf = + (2.08 ± 0.04) T in EuPd 2 and B hf = -(3.33 ± 0.02) T in EuPt 2. The Eu 153 resonance lines show well resolved quadrupolar structures with a line separation of 0.7 MHz in EuPd 2 and 1.4 MHz in EuPt 2. Analysis of the NMR results obtained in the isoelectronic pseudobinary series Eu x Ca 1− x Pd 2, Eu x Ba 1− x Pd 2, Eu x Ca 1− x Pt 2 and Eu 0.95 Ba 0.05 Pt 2 suggests that the observed quadrupolar interaction is partially related to a not completely divalent character of Eu in these compounds. This is in keeping with thermodynamic arguments given earlier by Miedema.

Structural properties of Gd(Co xIr 1−x) 2

The pseudobinary series Gd( Co x Ir 1− x ) 2 has been found to retain the C15 cubic Laves phase structure of its terminal compounds. It shows correlated sharp changes in structure and magnetic properties around x = 0.4. The lattice contracts while a Co moment begins to form. These effects may be interpreted as arising from an interaction between the Fermi surface and Brillouin zone faces.

Electron spin resonance in GdxY1-xIr2

Electron spin resonance measurements are reported for the (Gd, Y)Ir2 pseudobinary series. The results indicate that the ESR bottleneck of gadolinium can be broken by dilution with yttrium. The parameters relating to the relaxation rates have been determined by fitting the data to Hasegawa's theory (1959). The results are shown to be consistent with the behaviour of other gadolinium-transition metal compounds.

Intrinsic magnetic aftereffect in Dy(Co,Ni)2

A new type of time dependent magnetization has been found in the pseudobinary compound series Dy(Co,Ni)2. This has been associated with the narrow domain wall processes reported previously by several workers and is thought to be an intrinsic aftereffect connected with materials for which the ratio of the anisotropy and exchange energies is large.

Intrinsic coercivity in (TB, Y)3Co

The magnetic properties of the pseudobinary series (TB,Y)3Co have been investigated using a pulsed field magnetometer. The observed critical field behaviour has been associated with an intrinsic coercivity in the materials.