Synthesis, Magnetic Properties, Magnetic Entropy and Arrot Plot of Antiferromagnetic Frustrated Er_2Ti_2O_7 Compound

摘要

The pyrochlore Er_2~(3+)Ti_2~(4+)O_7~(2-) was synthesized via a ceramic method using two different oxides (Er_2O_3 and TiO_2). The compound was found to crystallize in the cubic system with the Fd3m space group (No. 227). A magnetic study, carried out at 2 and 300 K under an applied magnetic field μ_0H = 0.05 T, has revealed a complex magnetic structure at low temperature. The effective paramagnetic moment μ_(eff)~(exp), deduced from (χ - χ_0)~(-1) = f(T) curve, was found by assuming a zero moment on the transition metal atom Ti~(4+). The paramagnetic Curie-Weiss temperature θ_(CW)= -21.54 K, the nearest neighbor interaction J_(nn) = -2.30 K, the classical nearest neighbor J~(cl) = -8.65 K and the dipolar D_(nn) = 3.76 K interactions' values have revealed an antiferromagnetic behavior for Er_2Ti_2O_7 compound at low temperature. We have also studied the effects of the magnetic field splitting of rare-earth atom Er~(3+) in the compound Er_2Ti_2O_7 curved Arrott plots.