Magnetic order induced by hydrogen in superconducting RBa2Cu4O8 (R=Y,Gd) studied by Mössbauer and NQR techniques

I. Felner; U. Asaf; I. Nowik; E. R. Bauminger; L. Frenkel-Ben Yakar; S. D. Goren; C. Korn; H. Lütgemeier; S. Schmenn; H. Schone

doi:10.1103/PhysRevB.50.15858

Magnetic order induced by hydrogen in superconducting RBa2Cu4O8 (R=Y,Gd) studied by Mössbauer and NQR techniques

I. Felner, U. Asaf, I. Nowik, E. R. Bauminger, L. Frenkel-Ben Yakar, S. D. Goren, C. Korn, H. Lütgemeier, S. Schmenn, H. Schone

DOI 10.1103/PhysRevB.50.15858 · Physical Review B

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Abstract

Magnetic susceptibility, Mössbauer spectroscopy, nuclear quadrupole resonance of Cu (NQR), nuclear magnetic resonance of Cu in the hyperfine field of the antiferromagnetic state (AFNMR), and x-ray diffraction measurements were performed to study the superconducting and magnetic properties of hydrogen charged bulk YBa2Cu4O8Hy. For y<1 the c lattice parameter decreases with y. In contrast to Fe-doped YBa2Cu3O7Hy, where Tc decreases continuously with increasing y, we find here that for 1% Fe doped, Tc=59 K is unaffected by hydrogen charging, but the shielding fraction is reduced sharply from 38% for y=0 to 17% and 3% for y=1 and 1.85, respectively. The Mössbauer spectra for y=0 at T>90 K contain one doublet. The spectra for hydrogen charged samples, in addition to this doublet, contain a magnetic pattern composed of two sextets, between 4.1 K and TN=360 K. The relative amount of the magnetic pattern depends on hydrogen concentration. The Mössbauer spectrum obtained for y=1 is a superposition of spectra obtained for y=0 and those for y=2, showing a phase separation into magnetic and superconducting regions in YBa2Cu4O8Hy. NQR-AFNMR studies of YBa2Cu4O8Hy and GdBa2Cu4O8Hy samples indicate that magnetic order is induced only in the Cu(2) planes.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
YBa2(Cu0.99Fe0.01)4O8 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	59	Pressure not reported	onset
YBa2(Cu0.99Fe0.01)4O8Hy Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	59	Pressure not reported	onset
YBa2Cu3O7Hy Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown