First order phase transition from ferromagnetism to antiferromagnetism in Ce(Fe0.96_{0.96}Al0.04_{0.04})2_2

Taking the pseudobinary C15 Laves phase compound Ce(Fe$_{0.96}$Al$_{0.04}$)$_2$ as a paradigm for studying a ferromagnetic to antiferromagnetic phase transition, we present interesting thermomagnetic history effects in magnetotransport as well as magnetisation measurements across this phase transition. A comparison is made with history effects observed across the ferromagnetic to antiferromagnetic transition in R$_{0.5}$Sr$_{0.5}$MnO$_3$ crystals.Comment: 11 pages of text and 4 figures; submitted to Physical Review Letter

Variation of the magnetic moment and strain in epitaxial Cu/Ni/Cu sandwiches

We have studied the variation of the strain and the magnetic moment in epitaxial fct Ni(001) film structures using a combinaton of reflection high energy electron diffraction (RHEED) and x-ray magnetic circular dichroism. A 30 Å Cu/Ni step-wedge (30, 60, 90, and 150 Å)/600 Å Cu buffer/ Si(001) structure has been used to study the Ni thickness-dependent strain and magnetic moment. A decreased magnetic moment with decreasing Ni thickness is observed. A 30 Å Cu/50 Å Ni/step-wedged (600, 1000, 1500, and 2000 Å) Cu buffer/Si(001) was used to vary the degree of strain as determined by in situ RHEED measurements in the same Ni film by varying the Cu buffer layer thickness. Our study shows a possible correlation between the magnetic moment and strain. © 1997 American Institute of Physics