Influence of hydrogenation on
the magnetic properties of Er2Ni2Al
Chem.
Met. Alloys 9 (2016)
169-173
https://doi.org/10.30970/cma9.0350
Khrystyna
MILIYANCHUK,
Silvie MASKOVA, Ladislav HAVELA, Roman GLADYSHEVSKII
The magnetic
properties of Er2Ni2Al and Er2Ni2AlH5.3
have been studied in the temperature range 1.5-300 K. Er2Ni2Al
is an antiferromagnet with TN = 5 K,
as indicated by a pronounced maximum in the temperature dependence of the
magnetic susceptibility in magnetic fields below 1 T. In the paramagnetic
region, the susceptibility is described by the Curie-Weiss law, yielding an
effective moment of 9.69 µB/Er and θp = ‑14 K. The field
dependence of the magnetization in the ordered state exhibits a metamagnetic
transition around 2 T with a relatively wide hysteresis. The hydride Er2Ni2AlH5.3
does not show any magnetic ordering above T = 2 K.
The Curie-Weiss law fit of the magnetic susceptibility curve yields the values
9.63 µB/Er and θp = ‑10 K.
The magnetic behavior of both Er2Ni2Al and Er2Ni2AlH5.3
is supported by the shape of the temperature dependence of the heat capacity
curves. The upturn in C/T vs.
T for Er2Ni2AlH5.3,
which is suppressed by an applied magnetic field, is suggestive of magnetic
ordering at still lower temperatures. The dramatic suppression of Er–Er
exchange interactions (the size of the Er moments is generally stable) can be
understood as a consequence of H bonding, which reduces the concentration of
conduction electrons.
Magnetization curves for Er2Ni2Al
and Er2Ni2AlH5.3.
Keywords
Intermetallic /
Hydride / Magnetic properties / Heat capacity