where 𝛽 = 0.34 is the critical exponent related to pure ferromagnets. Based on Equation (3), a relationship between the change in Δ𝐻 012 and the effective magnetization 𝑀 can be further investigated (Figure ). According to Figure , the effective magnetization of the 1nm Ni NP is about 0.43 at its 𝑇 ! , and the corresponding change in Δ𝐻 012 is about 0.2 eV, which is equivalent to an effective temperature of 573 K in bulk Ni. In other words, the finite size effect of ferromagnetism has successfully reduced the working temperature of the MCE by about 150 K in the case of the Ni-C segregation-solution system.