MCE_of_EuCu2P2-CPB-Revised(5)

linearly extrapolated curve with the M1/ axis and plot Ms as a function of temperature, Ms(T). A similar procedure is also used for with the (H/M)1/ axis. Values for the critical exponents are obtained that are then reintroduced into the scaling of the modified Arrott plot. These procedures are repeated until the iterations converge and lead to the optimum fitting values. Figure 4 shows the modified Arrott plots of M1/ versus (H/M)1/ for EuCu1.75P2 with optimized = 0.45±0.03 and = 1.22±0.04 values, deduced from fitting Ms (T) and data using Equations (1) and (2), as shown in the inset of Fig. 4. The critical exponents from this static scaling analysis are related to the Widom scaling relationship, [26]

= 1 +

Using the above scaling relation and estimated values of and , the value of is determined to be 3.71±0.07. The value of is also determined using the Eq. (3) from two M(H) curves (shown in Fig. 5) with the nearest temperature (50 and 52 K) around TC. The value of is determined to be 3.93 and 3.58 for T = 50 and 52 K, respectively. These values are in agreement with each other indicated that the critical exponents obtained from the magnetization data are reliable. The critical values for EuCu1.75P2 are deviate from those of the mean field theory [27] which is probably related to the valence fluctuation of Eu contained compounds and/or the magnetic inhomogeneous in alloys.

According to Maxwell’s thermodynamic relation, the isothermal magnetic entropy changes associated with a magnetic field variation is given by

SM T, H Hmax

0 M H,T dH, (1) T H

where S, M, H, and T are the magnetic entropy, magnetization of the material, applied