ISSN:
1572-9605
Keywords:
doping
;
isotope effect
;
pseudogap
;
high-T c cuprates
;
crystal-field spectroscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Electrical Engineering, Measurement and Control Technology
,
Physics
Notes:
Abstract The temperature dependence of the relaxation rate of crystal-field excitations in the high-T c superconductors HoBa2Cu4O8 and HoBa2Cu3O x (6.4 〈 x 〈 7) was investigated by inelastic neutron scattering techniques. The data show clear evidence for the opening of an electronic gap in the normal state at T* 〉 T c in the underdoped regime as well as for slightly overdoped samples. For HoBa2Cu4O8 T* increases from 170 to 220 K upon oxygen isotope substitution (16O vs 18O). This huge isotope shift (which is absent in NMR and NQR experiments) suggests that the mechanism leading to an isotope effect on the pseudogap has to involve a time scale in the range 10−8 ≫ τ 〉 10−13 s.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1007806029650
