Quasi-two-dimensional transport properties of the layered superconductor Nd2−xCe x CuO4+δ

Pairing type change upon an increase in the cerium doping level in the Nd2 − x Ce x CuO4 + δ electronic superconductor

“…However, it is almost impossible to determine the value of δ exactly even for bulk samples. Comparison of the results of investigation of transport properties [17] with the results of analysis of neutron diffraction of the struc ture in annealed and oxygenated samples [18] con firms our ideas that oxygen occupies the O(3) apex positions in a Nd 2 -x Ce x CuO 4 + δ sample annealed in oxygen or not subjected to annealing, while these posi tion after annealing in the oxygen free atmosphere are vacated.…”

“…As was discussed in detail in [17], the value of δ (oxygen concentration) in the investigated films dur ing their processing cannot be determined exactly. The variation in the oxygen concentration can be deter mined only in bulk samples (e.g., in ceramics) using the thermogravimetric technique.…”

Hall Resistivity Correlations in Disordered Electron-Doped $$\hbox {Nd}_{2-x}\hbox {Ce}_x\hbox {CuO}_{4+\delta }$$ Nd 2 - x

“…Our previous investigations point out that the change in the oxygen concentration leads to a change in the degree of nonstoichiometric disorder [6,7,8,15]. Annealing in an oxygen-free atmosphere leads to a change in impurity scattering, while having little effect on the concentration of charge carriers and we will use the concepts of the theory of random two-dimensional systems where the parameter k F ℓ serves as the measure of disorder in the system.…”

“…Electron doping is generated by replacing the Nd 3+ ions in the parent compound Nd 2 CuO 4 with Ce 4+ to form a non-superconducting antiferromagnet Nd 2−x Ce x CuO 4+δ [2]. Additional annealing in oxygen-free atmosphere leads to suppress the static AF order and to appearance of the superconductivity [3,4,5,6]. During the annealing process a certain amount of the oxygen excess is removed and the lattice structure isn't practically destroyed [4,7,8].…”

Resistivity tensor correlations in the mixed state of electron-doped superconductor Nd2−xCe x CuO4+δCharikova1, Shelushinina2, Harus3 et al. 2016Physica C: Superconductivity and its Applications9070View full textAdd to dashboardCite

“…The films were subjected to a heat treatment . Annealing in an oxygen-free atmosphere leads to a change in impurity scattering, while having little effect on the concentration of charge carriers 34 . We will use the concepts of the theory of random two-dimensional systems where the parameter k F ℓ serves as the measure of disorder in the system and can be found from the experimental value of ρ xx 37 :…”