Effect of an applied magnetic field on the charge-density-wave carrier concentration inNbSe3

Large enhancement of the resistive anomaly in the pentatelluride materialsHfTe5andZrTe5Tritt1, Lowhorn2, Littleton3 et al. 1999Phys. Rev. B7211560View full textAdd to dashboardCite

“…18,19 It was shown, conclusively, that the number of carriers in the CDW state was not being affected by the magnetic field, to within an experimental resolution of a few percent. 20,21 It was concluded that the large MR was due to the changing band character of the material through the CDW transition, where the normal state semimetallic character was enhanced. The system is much more semimetallic at temperatures below the CDW transition, losing a large part of its Fermi surface ͑Ϸ30% of the Fermi surface at T 1 and 65% of the remaining Fermi surface at T 2 ) and exhibits the large MR that is characteristic of narrow overlap semimetallic materials ͑such as Bi and Sb͒.…”

Pressure effect on large magnetoresistance in the lower charge-density-wave transition ofNbSe3

“…These results may also be negative for the change in the CDW order parameter with magnetic field. Both the results of the magnetotransport and the x-ray scattering lead us to the prediction in which the large magnetoresistance appearing below T c2 could be simply explained by considering light carriers in small ungapped pockets of the Fermi surface generated by the imperfect nesting on the formation of the T c2 -CDW state, as pointed out by Tritt et al 11,12 However, quantitative estimates of such effects have not yet been reported.…”

“…Similar models have been accepted as a standard model for a formation mechanism of the field-induced spin-density-wave ͑SDW͒ observed in Q1D organic conductors. 10 Many transport experiments such as narrow-band noise, 11,12 Hall effect, 13 and the thermopower 14 have been tried in the transverse magnetic fields to investigate whether the CDW order parameter of NbSe 3 is enhanced by the magnetic field. However, these results were negative for the change in the CDW order parameter with magnetic field.…”

Magnetoresistance of quasi-two-dimensional purple bronzesAMo6O17Tian1, Yue2, Zhang3 2002Phys. Rev. B

“…8 Using NbSe 3 , Parilla et al 9 and Hundley et al 10 gave evidence of magnetic-field-induced enhanced gaps by transport measurements. They observed a 30% increase of the CDW carriers at 30 K under a field of 7.5 T. However, Tritt et al 11 presented negative results; they found that even at H ϭ10 T the effect of the magnetic field on the MR was less than 5%. In addition, recent studies of the pressure effect on large MR, 12 and for x-ray scattering 13 in magnetic fields up to 10 T in NbSe 3 , further suggested that the large MR might not result from the change in the CDW order parameter with magnetic field but rather from light carriers in small ungapped pockets of the Fermi surface ͑FS͒ generated by an imperfect nesting of the FS.…”