Anomalous charge transport of the parent antiferromagnet Bi2Sr2 RCu2O8

Thermopower of Bi2Sr2Ca1-xRxCu2Oy(R = Gd, Pr) single crystals

“…This pseudogap is supposed to be associated with a phenomenon affecting the density of states or the antiferromagnetic excitations [29]. The relationship between this scaling characteristic temperature and the carrier concentration has been found very close to those found by scaling the NMR Knight shift and neutron scattering [12,29]. Scaling on other normal-state transport properties of HTSCs has also been established and found to be similar to ours.…”

“…This scaling behaviour may be associated with the normal state pseudogap with T scale being the pseudogap characteristic temperature. Recently, a gaplike feature in the electric spectrum of low energy excitation and a series of characteristic temperatures have been found in the underdoped HTSCs, from NMR [27], optical conductivity [28] and thermopower [9,12]. This pseudogap is supposed to be associated with a phenomenon affecting the density of states or the antiferromagnetic excitations [29].…”

“…In cuprate superconductors, a nearly universal relationship between the TEP value at room temperature, the hole concentration on the CuO 2 planes and the transition temperature has been brought forth by Obertelli et al [2] and used as a gauge to determine the hole concentration. Although some common features of the TEP have been found in La, Y, Bi, Tl and Hg systems over the years [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19], there has been no satisfactory explanation for the behaviour of the TEP up to now, and a wealth of theoretical models and experiments remain controversial. Furthermore, the significant changes of the electric properties near the Fermi level E F are still unclear and worth being investigated.…”

“…On the other hand, in the HTSCs, it is natural to take into account the influence induced by incorporating the dopant itself on the Fermi level. The Bi 2 Sr 2 CaCu 2 O y (Bi2212) superconductor has been widely studied [3,[10][11][12][13][14][15][20][21][22][23] since not only can it be prepared over a wide doping range, but also it has no complex Cu-O chain which might affect the electronic state. Nonisovalent substitution for the Ca of Bi2212 by rare-earth elements (R) is a fruitful way to directly change the charge carriers and the band spectrum, and hence the transport behaviour.…”

Out-of-plane dielectric constant and insulator-superconductor transition in Bi2Sr2Dy1-xErxCu2O8single crystals

“…We have studied the charge transport of the parent insulator of Bi-2212 [15][16][17], and have found that the physics is as rich as the physics of HTSC themselves. In this paper, we report on measurement and analysis of the dielectric constant of Bi 2 Sr 2 Er 1−x Dy x Cu 2 O 8 single crystals along the out-of-plane direction.…”