Magnetic and resonance studies of the laves phase compounds GdT₂ (T ≡ Rh, Ir, Pt, Ru, Mn)

A detailed study was made of the Laves phase compounds GdT₂ (T ≡ Rh, Ir, Pt, Ru, Mn). The study was carried out by observing the spin-echo nuclear magnetic resonance (NMR) of ¹⁶⁵Ho, which was introduced as a dilute substitutional impurity, the electron spin resonance (ESR) of Gd³⁺ and magnetic measurements. The NMR of holmium reveals the presence of a strong crystalline electric field in these compounds, particularly in GdRh₂ and GdMn₂. Except for GdMn₂, for which the extraction of ESR parameters was not possible, the investigation suggests that the gadolinium ESR is bottlenecked in all the compounds studied. Both the magnetic and the ESR studies of GdMn₂ reveal magnetic and structural phase transitions at 283 K and 106 K respectively. The g shift is negative for gadolinium in GdRu₂ for which a saturation moment of (6.31 ± 0.15)μ_B is found. In other alloys the g shift is positive and the saturation moment for gadolinium is found to be approximately 7μ_B which is considerably higher than values reported earlier and in excellent agreement with values reported more recently.