Competition between the crystal field and the exchange field in Er3+ doped NdMnO3

A careful investigation of specific heat shows that the ground state splitting of Nd3þ has been modified by the Er3þ doping, as it shows a nonlinear dependence on the Er3þ doping rate, due to the competition between the crystal field and the exchange field. This competition could be further confirmed by the anomalies in the magnetic entropy and the ground state splitting found in Nd0.9Er0.1MnO3. On the contrary, the ground state splitting of Er3þ has a linear dependence on the doping rate, indicating its stronger dependence on the crystal field rather than the exchange field.