Disorder effects on the charge-density waves structure in V- and W-doped blue bronzes: Friedel oscillations and charge-density wave pinning
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin Boite Postale 48, 91192 Gif-sur-Yvette Cedex (France)
- Laboratoire de Physique des Solides, CNRS UMR 8502, Batiment 510, Universite Paris-Sud, 91405 Orsay Cedex (France)
- Laboratoire de Physique Theorique et Modeles Statistiques, CNRS UMR 8626, Batiment 100, Universite Paris-Sud, 91405 Orsay Cedex (France)
- Laboratoire d'Etude des Proprietes Electroniques des Solides-CNRS, Boite Postale 166, 38042 Grenoble Cedex (France)
- Laboratoire de Cristallographie CNRS, Boite Postale 166, 38048 Grenoble Cedex (France)
We present an x-ray diffuse scattering study of the charge-density wave (CDW) structure in the doped blue bronzes K{sub 0.3}(Mo{sub 1-x}V{sub x})O{sub 3} (x=2.8%), Rb{sub 0.3}(Mo{sub 1-x}V{sub x})O{sub 3} (x=1.44% and 0.28%), and K{sub 0.3}(Mo{sub 1-x}W{sub x})O{sub 3} (x=2%). At low temperature, the {+-}2k{sub F} satellite reflections are broadened in all four compounds, and shifted in V-doped compounds. Moreover, we have observed an intensity asymmetry of the {+-}2k{sub F} satellite reflections relative to the pure compound, and a profile asymmetry of each satellite reflections. We show that both effects, intensity and profile asymmetry, give access to the local properties of CDW in disordered systems, including the pinning and the phase shifts around impurities. This leads us to propose a complete scenario of the pinning in doped blue bronzes. In the V-doped compounds, we show that the profile asymmetry is due to Friedel oscillations around the charged V substituent and that the intensity asymmetry is related to the strong pinning of the CDW. In the W-doped crystal, the CDW is weakly pinned in regions containing a few tens of neutral W substituents and the CDW phase is slightly distorted around the W impurities. Exact calculations are presented to sustain these ideas.
- OSTI ID:
- 20853850
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 74, Issue 17; Other Information: DOI: 10.1103/PhysRevB.74.174102; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ASYMMETRY
BRONZE
CHARGE DENSITY
CONCENTRATION RATIO
CRYSTALS
DIFFUSE SCATTERING
DOPED MATERIALS
MOLYBDENUM OXIDES
OSCILLATIONS
PHASE SHIFT
POTASSIUM COMPOUNDS
REFLECTION
RUBIDIUM COMPOUNDS
TUNGSTEN ADDITIONS
VANADIUM ADDITIONS
X RADIATION
X-RAY DIFFRACTION