L. Morellon et al., MAGNETOELASTIC AND PRESSURE EFFECTS AT THE ANTIFERRO-FERROMAGNETIC TRANSITION IN HF1-XTAXFE2-Y ALLOYS, Journal of applied physics, 80(12), 1996, pp. 6911-6914
Magnetostriction measurements using high-pulsed magnetic fields up to
14 T and thermal expansion measurements under hydrostatic pressure up
to 12 kbar have been performed in Hf1-xTaxFe2-y alloys with x=0.17 and
0.15 and y=0.02. These compounds have a first-order magnetic phase tr
ansition from an antiferromagnetic (AF) high-temperature state to a fe
rromagnetic (F) low-temperature state at T-AF-F=246 and 290 K, respect
ively. This transition is accompanied by a volume expansion from the l
ow-volume AF state to the high-volume F state of Delta V/V approximate
to 0.56% and 0.38% for x=0.17 and 0.15, respectively. Hydrostatic pre
ssure decreases significantly the AF-F transition temperature, whereas
the thermal expansion anomaly becomes more pronounced. The dependence
of T-AF-F on pressure follows a quadratic behavior and T-AF-F reaches
a value of 106 K at 10.5 kbar for x=0.17. In search of high magnetost
rictive materials, we have found a giant volume magnetostriction value
(e.g., omega approximate to 0.7% for the x=0.17 compound) in these al
loys at a moderate applied magnetic field within the AF phase near roo
m temperature, making these alloys potential candidates for magnetostr
ictive transducers. (C) 1996 American Institute of Physics.