Relaxation of the normal electrical resistivity induced by high-pressure in strongly underdoped YBa2Cu3O7–δ single crystals

Effect of Long Aging on the Resistivity Properties of Aluminum Doped YBa2Cu3−y Al y O7−δ Single Crystals with a Given Twin Boundary Topology

“…Additionally, it is consistent with the step-like form, which is observed after aging, showing signs indicating the appearance of phase separation in their volume [4,14]. This is also supported by the presence of a clearly pronounced additional peak in the dependence dρ ab /dT versus T. According to previous work [3,4,14], these peaks correspond to the T c of different phases, differing in oxygen content within the volume in the crystal and therefore having different Т с .…”

Modification by high pressure of fluctuation paraconductivity of underdoped HoBa2Cu3O7-δ single crystals

“…1, the resistive transitions of our sample are characterized by a clearly expressed stepwise form. This, apparently, indicates the presence in the sample of at least two phases, with correspondingly, different critical temperature (T c1 and T c2 ) of the transition to the superconducting state [42]. In Fig.…”

“…As it has been determined previously [42] the high pressure application to HTSC samples with a developed twin structure may facilitate the flow in the system of ascending diffusion processes, when part of the oxygen from the phase with the lower T c migrates into the phase with the higher critical temperature, and by decreasing pressure, occur the opposite redistribution. Indeed, as it is shown in the inset in Fig.…”

“…As is known, the presence of the labile oxygen [32,33] in the ReBa 2 Cu 3 O 7-d (Re=Y, or another rare earth ion) compounds, can contribute to the emergence of an non-equilibrium state, which can occur at high pressures [34,35], ''hopping'' changes in temperature [36,37] and long-term storage [38][39][40] and, in turn, may contribute to the process of phase separation [41,42], ascending diffusion [43,44] and the emergence of various kinds of superstructures [45,46]. All these processes have a significant impact on the physical properties of HTSC in the normal and in superconducting states.…”

Effect of Structural Relaxation on the Metal–Insulator Transition in Heavily Underdoped YBa $$_2$$ 2 Cu $$_3$$ 3 O $$_{7-\delta }$$ 7 - δ Single Crystals

“…The labile component, in turn, conduces to the B O. V. Dobrovolskiy Dobrovolskiy@Physik.uni-frankfurt.de 1 V. Karazin National University, Kharkiv 61077, Ukraine appearance in the structure of the so-called "non-equilibrium" state [13,14] which can be relatively easily induced by application of a high pressure [15,16] or an abrupt temperature change [17,18]. The relaxation processes appearing in this state essentially affect the critical and electro-transport parameters of the compound, thereby suppressing or, on the contrary, enhancing the above-named peculiarities observed in the normal state [19][20][21].…”