Magnetic and Magnetostrictive Properties of Tb$_x$Dy$_0.7 - x$Pr$_0.3$(Fe$_0.9$B$_0.1$)$_1.93$Compounds and Their Composites

Tb
$_x$
Dy
$_0.7-x$
Pr
$_0.3$
(Fe
$_0.9$
B
$_0.1$
)
$_1.93$
(TDPFB
$_x$
) multicomponent Laves compounds with
$x$
slightly varying in the anisotropy minimization region of 0.16–0.25 were prepared, together with their epoxy-bonded particulate composites with 53-vol% TDPFB
$_x$
particles, so as to investigate the dependence of their magnetic and magnetostrictive properties on
$x$
as a function of magnetic field. The composites showed similar qualitative trends in properties with the compounds for all
$x$
. The TDPFB
$_x = 0.22$
compound and composite exhibited the fastest saturation of magnetization with the lowest coercivity besides the largest low-field (
$≪$
400 kA/m) magnetostrictions
$lambda_a(= lambda_vert vert-lambda_bot)$
, piezomagnetic coefficients
$d_33$
, and ratios of
$lambda_a$
to maximum
$lambda_a$
$(lambda_a lambda_ amax)$
. The TDPFB
$_x = 0.22$
composite demonstrated a large
$lambda_a$
of 490 ppm at 400 kA/m and a high
$d_33$
of 1.4 nm/A at 160 kA/m. These values approached to 79% and 82% of its compound values at the same field levels. The high magnetostrictions combined with the low magnetic anisotropy could make the TDPFB
$_x = 0.22$
compound and composite be promising magnetostrictive materials.