Abstract
We have carried out angle-resolved photoemission spectroscopy (ARPES) and spectromicroscopy studies to understand the metal–insulator transition (MIT) observed in sodium tungsten bronzes, Na x WO3. The experimentally determined band structure is compared with the theoretical calculation based on full-potential linear augmented plane-wave method. It has been found that there is a good gross agreement between experiment and theory. ARPES spectra on the insulating sample show that the states near E F are localized due to the random distribution of Na in WO3 lattice which causes strong disorder in the system. Our spectromicroscopy measurements on both insulating and metallic samples do not approve percolation model to explain MIT in Na x WO3. Photoemission spectroscopy on metallic samples does not show any Na-induced impurity band (level), which was one of the models to explain MIT. Electron-like Fermi surface(s) has been found from our experiment for metallic samples at the Γ(X) point which shows good agreement with band calculation.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
C G Granqvist, Handbook of inorganic electrochromic materials (Elsevier, Amsterdam, 1995)
P M S Monk, R J Mortimer and D R Rosseinsky, Electrochromism: Fundamentals and applications (VCH, Weinheim, 1995)
S Raj, T Sato, S Souma, T Takahashi, D D Sarma and P Mahadevan, Mod. Phys. Lett. B 23, 2819 (2009)
A S Ribnick, B Post and E Banks, Adv. Chem. Ser. 39, 246 (1963)
H R Shanks, P H Slides and G C Danielson, Adv. Chem. Ser. 39, 237 (1963)
A R Mackintosh, J. Chem. Phys. 38, 1991 (1963)
P W Anderson, Phys. Rev. 109, 1492 (1958)
D P Tunstall and W Ramage, J. Phys. C: Solid State Phys. 13, 725 (1980)
S Oishi, N Endo and K Kitajima, Nippon Kagaku Kaishi No. 11 p. 891 (The Chemical Society of Japan, Japan, 1995)
H R Shanks, J. Crystal Growth 13/14, 433 (1972)
S Paul, A Ghosh, P Dudin, A Barinov, A Chakraborty, S Ray, D D Sarma, S Oishi and S Raj, Solid State Commun. 166, 66 (2013)
P Dudin, P Lacovig, C Fava, E Nicolini, A Bianco, G Cautero and A Barinov, J. Synchrotron Radiat. 17, 445 (2010)
A Einstein, Ann. Der Physik 325, 199 (1906)
S Raj, D Hashimoto, H Matsui, S Souma, T Sato, T Takahashi, S Ray, A Chakraborty, D D Sarma, P Mahadevan, W H McCarroll and M Greenblatt, Phys. Rev. B 72, 125125 (2005)
S Raj, D Hashimoto, H Matsui, S Souma, T Sato, T Takahashi, D D Sarma, P Mahadevan and S Oishi, Phys. Rev. Lett. 96, 147603 (2006)
S Raj, H Matsui, S Souma, T Sato, T Takahashi, A Chakraborty, D D Sarma, P Mahadevan, S Oishi, W H McCarroll and M Greenblatt, Phys. Rev. B 75, 155116 (2007)
S Raj, A Chakraborty, D Choudhury, T Sato, T Takahashi, P Mahadevan, J Fujii, I Vobornik and D D Sarma, Phys. Rev. B 79, 035119 (2009)
S Paul, A Ghosh, A Chakraborty, L Petaccia, D Topwal, D D Sarma, S Oishi and S Raj, Solid State Commun. 152, 493 (2012)
N F Mott, Phil. Mag. 35, 111 (1977)
D J Singh and L Nordström, Plane waves, pseudopotentials and the LAPW method (Springer, New York, 2006)
ELK code: http://elk.sourceforge.net
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
PAUL, S., RAJ, S. Understanding metal–insulator transition in sodium tungsten bronze. Pramana - J Phys 84, 957–966 (2015). https://doi.org/10.1007/s12043-015-0993-9
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12043-015-0993-9