Magnetostriction of rare earth2-iron17compounds

The magnetostrictions of polycrystal R
2
Fe
17
compounds (R=Y,Pr,Sm,Tb,Dy,Ho,Er, and Tm) were measured in the temperature range from 4.2K to 340K in magnetic fields up to 25kOe. Pr
2
Fe
17
exhibited the highest magnetostriction at OK of all the compounds studied: λ
t
(0) = 1250 × 10
^-6
. For R=Pr,Ho,Er, and Tm compounds the volume magnetostriction and thermal expansion coefficients were measured near the magnetic ordering temperature T
c
. These are compared using classical thermodynamic theory.