The Adiabatic Temperature Changes in the Vicinity of the First-Order Paramagnetic-Ferromagnetic Transition in the Ni-Mn-In-B Heusler Alloy

The magnetocaloric properties of Ni-Mn-In-B Heusler alloy have been studied using direct measurements of the adiabatic temperature change (Δ
T
_AD
(
T
,
H
)) , and indirectly by magnetization (
M
(
T
,
H
)), differential scanning calorimetry, and specific heat (
C
_P
(
T
,
H
)) measurements. The presence of a first-order ferromagnetic-paramagnetic transition has been detected for Ni
₅₀
Mn
_34.8
In
_14.2
B at 320 K. The magnetocaloric parameters, i.e., the magnetic entropy change, Δ
S
_M
= (2.9-3.2) J/kgK, and the adiabatic temperature change, Δ
T
_AD
= (1.3-1.52) K, have been evaluated for Δμ
₀
H
= 1.8 T from
C
_P
(
T
,
H
) and M(T,H), and from
C
_P
(
T
,
H
) and direct Δ
T
_AD
(
T
,
H
) measurements, respectively, in the vicinity of the first-order transition temperature. The extracted magnetocaloric parameters are comparable to that of Gd.