Investigation of Magnetocaloric Properties and Critical Behavior in Layered Type (Ce0.65La0.35)Mn2Ge2 Room Temperature Ferromagnet

The quaternary (Ce
_0.65
La
_0.35
)Mn
₂
Ge
₂
has been prepared by arc melting route from a low-cost misch metal (Ce
_0.65
La
_0.35
) and its magnetic and magnetocaloric properties have been evaluated. (Ce
_0.65
La
_0.35
)Mn
₂
Ge
₂
belonging to body-centered tetragonal (BCT) structure of space group of I4/mmm exhibits a second-order transition from ferro to antiferromagnetic at 320 K. The field-dependent magnetization confirms the ferromagnetic nature below Curie temperature (320 K), showing the magnetization of 32 emu/g and the coercivity of 5.3 kOe at 10 K. The isothermal magnetic entropy change (
$\Delta S_{M}$
) has been determined around transition temperature (
$T_{C}$
) at various applied fields and the maximum
$-\Delta S_{M}$
values are found to be 0.76–2.09 J/kg
$\cdot \text{K}$
at an applied field of 10–50 kOe. The corresponding relative cooling power (RCP) values are 13–63 J/kg. The modified Arrott plots and field- and temperature-dependent magnetization in the vicinity of ferromagnetic-to-antiferromagnetic transition have been used to determine the critical behavior of (Ce
_0.65
La
_0.35
)Mn
₂
Ge
₂
. The values of the associated critical exponents
$\delta $
,
$\beta $
, and
$\gamma $
are 4.77, 0.36, and 1.36, respectively, which are close to the values of 3-D Heisenberg theory indicating long-range magnetic interaction in (Ce
_0.65
La
_0.35
)Mn
₂
Ge
₂
compound.