Critical behavior near room temperature in La0.75Ca0.05Na0.20MnO3 sample.

The critical behavior of La0.75Ca0.05Na0.20MnO3 was studied at around room temperature via magnetization measurements. From the relative slope, we deduced that the Tricritical Mean-Field model was the most suitable model. The estimated critical exponents were found to be ß = 0.24 ± 0.004, γ = 0.98 ± 0.065 and δ = 5.08 at T C = 300 K. These critical exponents satisfied the Widom scaling relation δ = 1 + γ/ß, implying the reliability of our values. Based on the critical exponents, the magnetization-field-temperature (M-µ 0 H-T) data around T C collapsed into two curves, obeying the single scaling equation with ε = (T - T C)/T C being the reduced temperature. These results suggest short-range interaction in our sample.