The complex dynamic Young’s modulus of ceramic Nd22xCexCuO4 with x ¼ 0; 0.05 and 0.20 has been measured from 1.5 to 100 K at frequencies of 1–10 kHz. In the undoped sample the modulus starts decreasing below ,20 K, instead of approaching a constant value as in a normal solid. The modulus minimum has been interpreted in terms of paraelastic contribution from the relaxation of the Nd3þ 4f electrons between the levels of the ground state doublet, which is split by the interaction with the antiferromagnetically ordered Cu sublattice. The value of the splitting is found to be 0.34 meV, in excellent agreement with inelastic neutron scattering, infrared and specific heat experiments. With doping, the anomaly shifts to lower temperature and decreases in amplitude, consistently with a reduction of the local field from the Cu sublattice

Acoustic measurement of the low-energy excitations in Nd2-xCexCuO4+d

FERRETTI, MAURIZIO
2003-01-01

Abstract

The complex dynamic Young’s modulus of ceramic Nd22xCexCuO4 with x ¼ 0; 0.05 and 0.20 has been measured from 1.5 to 100 K at frequencies of 1–10 kHz. In the undoped sample the modulus starts decreasing below ,20 K, instead of approaching a constant value as in a normal solid. The modulus minimum has been interpreted in terms of paraelastic contribution from the relaxation of the Nd3þ 4f electrons between the levels of the ground state doublet, which is split by the interaction with the antiferromagnetically ordered Cu sublattice. The value of the splitting is found to be 0.34 meV, in excellent agreement with inelastic neutron scattering, infrared and specific heat experiments. With doping, the anomaly shifts to lower temperature and decreases in amplitude, consistently with a reduction of the local field from the Cu sublattice
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11567/317512
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