The DX centre
T.N. Morgan
Semiconductor Science and Technology
We have used resistivity and Hall measurements on ion-irradiated thin films of the cuprate superconductor Nd2-xCexCuO4-δ (NCCO) to explore the full range of transport behavior as a function of disorder in this material from superconductivity to variable-range-hopping (VRH) conduction. The cotangent of the Hall angle (cot ΘH) in lightly irradiated samples exhibited a temperature dependence related to that of resistivity, providing support for a recent theory of Varma and Abrahams. The most highly irradiated samples exhibited p(T)∝exp[(To/T)0.5] at low temperatures, evidence of VRH in the presence of a Coulomb gap. The change of the Hall number with disorder and temperature is analyzed in the framework of possible two-carrier conduction in NCCO.
T.N. Morgan
Semiconductor Science and Technology
R.D. Murphy, R.O. Watts
Journal of Low Temperature Physics
Ming L. Yu
Physical Review B
Mitsuru Ueda, Hideharu Mori, et al.
Journal of Polymer Science Part A: Polymer Chemistry