Magnetic flux dynamics and structural features in fluorinated HgBa 2 CuO 4 as probed by<mml:math xmlns:mml="http://www.w3.org/1998/Math/…
2000; American Physical Society; Volume: 61; Issue: 21 Linguagem: Inglês
10.1103/physrevb.61.14370
ISSN1095-3795
AutoresA.A. Gippius, Е. Н. Морозова, Evgeny V. Antipov, Artem M. Abakumov, Marina G. Rozova, Klaus Lüders, W. Hoffmann, Gerd Buntkowsky, O. Klein,
Tópico(s)Inorganic Fluorides and Related Compounds
Resumo${}^{19}\mathrm{F}$ NMR spectra and spin-lattice relaxation rates have been measured on two powder ${\mathrm{HgBa}}_{2}{\mathrm{CuO}}_{4}{\mathrm{F}}_{x}$ samples. The results combined with our neutron powder-diffraction data [A. M. Abakumov et al., Phys. Rev. Lett. 80, 385 (1998)] confirm that fluorine atoms can be successfully incorporated in the lattice of superconducting Hg-1201 phase in the nonstoichiometric O3 site. Partial occupation of another oxygen position by fluorine atoms reveals to be possible with the increase of F content. The temperature dependence of the ${}^{19}\mathrm{F}$ NMR linewidth reveals the crossover at 35 K in the magnetic-flux line structure between the low-temperature latticelike regime and high-temperature ``melted'' regime. For the ${1/T}_{1}$ temperature dependence a maximum has been found at 65 K indicating the strong influence of magnetic-flux line motion on the ${}^{19}\mathrm{F}$ spin-lattice relaxation rate.
Referência(s)