Magnetic susceptibility of optimally doped HgBa2CuO4+δ

Abstract

The magnitude of the powder spin susceptibility of an optimally doped superconductor HgBa2CuO 4+δ (Hg1201) in the normal state is found to be nearly the same as that of La2−xSrxCuO4 near the optimally doped level. The Stoner enhancement factor of Hg1201 is larger than that of La2−xSrxCuO4. The magnitude correlation of the Stoner enhancement factor is inconsistent with the effect of the recent theoretical Coulomb repulsion between 3d electrons and that of the superexchange intereraction of a charge transfer type.

Ni-Driven Evolution of Pseudogap and Superconducting Gap in Underdoped Cuprate

“…Rather, this is an increased Stoner factor that plays a role in the enhancement of B Pauli with increased y in LSCNO. This tendency is in contradiction with that found in LSCO, where decreasing of B c2 with underdoping is accompanied by a decrease in χ s , and thus a decrease in S factor as well [47,51].…”

“…For y=0.035 this gives χ VV = 2.4 × 10 −5 emu/(Oe mole). The diamagnetic inner-shell electron contribution χ core = −9.8 × 10 −5 emu/(Oe mole) [51] is not altered. Finally, this leads to the linear increase of the spin susceptibility †2 χ for y = 0.035 is interpolation of the results for targets from [28].…”

“…where χ s (T ) stands for spin susceptibility, shows more clearly the spin-orbit partition of LSCNO susceptibility [51]. The Curie-like term needs to be subtracted to obtain the intrinsic spin susceptibility of hole-doped CuO 2 planes.…”

“…As χ VV (y=0) we took χ for Sc 2 CuO 4 , 2.3 × 10 −5 emu/(Oe mole) [52]. Taking χ P ≈ 0.7 × 10 −4 emu/(Oe mole) from the band theoretical calculations [51,53] for LSCO15 yields S ≈ 2.6, which is larger than S = 2.0-2.3 (at 320 K) reported for LSCO with x = 0.13-0.18 in [51]. Substitution of y Ni 2+ ions having 3d 8 shell (χ VV ≈ 5×10 −5 emu/(Oe mole) [54] with Cu 2+ ions having still incomplete 3d 9 shell increases χ VV of the system as χ VV [10 −5 emu/(Oe mole)] = 2.3(1−y) + 5y.…”