Showing papers by "Sheldon Schultz published in 1987"
TL;DR: BaCuO2 is found to be the main source of the low-temperature EPR signal and of the magnetic susceptibility which has been reported for YBa2Cu3O9-x above Tc.
Abstract: Many electron-paramagnetic-resonance (EPR) and magnetic susceptibility measurements for the high-Tc superconductors of the form RBa2Cu3O9-x (R=Y or a rare earth) have been reported. Excluding local moment resonances due solely to the R atoms, we show that all of the EPR measurements known to us are not intrinsic to the superconducting phase, but rather are due to low concentrations of spurious phases typically present in the samples. BaCuO2 is found to be the main source of the low-temperature EPR signal and of the magnetic susceptibility which has been reported for YBa2Cu3O9-x above Tc. © 1987 The American Physical Society.
65 citations
TL;DR: In this paper, the authors measured electron paramagnetic resonance (EPR), electrical resistivity, and dc magnetic susceptibility from 2 K -300 K for the high T c oxide superconductor EuBa 2 Cu 3 O 9−x, either undoped or doped with 3d ions (Cr, Mn, Fe, Ni, Co, or Zn), which presumably substitute at the Cu sites.
48 citations
TL;DR: In this article, the decay of the magnetization with time does not follow a simple log t relation, and an empirical model which allows one to relate values of coercive field, H c, obtained with a 60 Hz B-H looper, to that measured with a slow VSM field cycle is presented.
Abstract: We report on magnetization time decay data on several commercial and experimental tapes (γ-Fe 2 O 3 , Co-doped, and Co-Cr) measured at room temperature between 1s and 104s. We found that the decay of the magnetization with time does not follow a simple log t relation. We analyze our data with an empirical model which allows one to relate values of coercive field, H c , obtained with a 60 Hz B-H looper, to that measured with a slow VSM field cycle. The methodology we have developed appears to have promise as a means of correlating data over ten orders of magnitude of time from 10-6s to 104s.
33 citations
TL;DR: In this paper, low temperature (T>0.6K ) Electron Spin Resonance (ESR) experiments were carried out for the Heavy-Fermion compounds UBe 13 and UPt 3 doped with several rare Earth ions.
14 citations
01 Jan 1987
TL;DR: In this paper, a 30 K transition in La2-yBayCuO4-x and YBa2Cu2O9-x has been shown to have a Tc well above liquid nitrogen temperatures.
Abstract: After years of searching for superconductors with higher transition temperatures, an incredible success has been achieved in recent months, as a consequence of the discovery of Bednorz and Muller of a 30 K transition in La2-yBayCuO4-x,1 followed by the subsequent findings that YBa2Cu2O9-x has a Tc well above liquid nitrogen temperatures.2,3 These discoveries have resulted in an explosive growth of interest in the field, with the present challenge being to explain the pertinent superconducting mechanisms.
3 citations
TL;DR: In this paper, the temperature and field dependence of the dc magnetization of Fe atoms on polycrystalline Ag substrates in the range 0.1-100 monolayers equivalent mass coverage was measured.
Abstract: We have made measurements of the temperature and field dependence of the dc magnetization of Fe atoms deposited on polycrystalline Ag substrates in the range 0.1–100 monolayers equivalent mass coverage. Our experimental technique is to couple an ultrahigh vacuum sample preparation and transport chamber to a SQUID dc magnetometer. We shall present an analysis of these data and a comparison of the deduced saturation moment and anisotropy constant with the theoretical and experimental results of the companion papers in this symposium.
2 citations