Giant magnetocaloric effect in Tb5Ge2-xSi2-xMn2x compounds

The crystal structure, magnetic and magnetocaloriccharacteristics of the pseduo ternary compounds ofTb$_{5}$Ge$_{2-x}$Si$_{2-x}$Mn$_{2x}$ (0 $leq $ 2$x$ $leq$ 0.1)were investigated by x-ray powder diffraction and magnetizationmeasurements. The x-ray powder diffraction results show that allcompounds preserve the monoclinic phase as the majority phase andall the synthesized compounds were observed to be ferromagnetic frommagnetization measurements. Magnetic phase transitions wereinterpreted in terms of Landau theory. Maximum isothermal magneticentropy change value(20.84~J,$cdot$,kg$^{-1}$,$cdot$,K$^{-1}$) was found forTb$_{5}$Ge$_{1.95}$Si$_{1.95}$Mn$_{0.1}$ at around 123~K in themagnetic field change of 5~T.