PDF Publication Title:
Text from PDF Page: 035
1. INTRODUCTION Allen (ZSA) (99). It has given a straightforward method for the classification of oxides according to the interplay between Coulomb correlation energy U of d electrons and charge transfer energy ∆. Two cases are considered: (1)when U < ∆ the Mott-Hubbard d − d gap with energy U is formed, with accompanying dn + dn → dn−1 + dn+1 charge fluctuations; (2) when U > ∆ a gap of p−d type with energy ∆ is formed, and compound becomes charge-transfer insulator with dn + dn → dn+1 + dnL electronic fluctua- tions, along with formation of a hole L on the oxygen atom in the valence p band (28). 1.3 Metal-insulator transitions Variety of metal-insulator transitions exist due to complicated interplay between various factors (59). In transition metal oxides the factors include the d electron bandwith, Coulomb repulsion, spin-orbit coupling. However the most basic clas- sification is done depending on whether the primary interaction is electron-ion or electron-electron. The first group neglects existence of many electrons and their interaction and consists of: • Bloch-Wilson (band) insulators, • Peierls insulators, • Anderson insulators. Interactions of electrons give rise to group of insulators of Mott type. Especially important are electron correlations which are the main feature related to appear- ance of MIT. Few types of transitions in transition metal oxides (TMOs) have already been identified, although this set is not complete: • Mott or Mott-Hubbard insulator, • charge-transfer insulator, • Slater insulator. The first three appear in compounds with symmetric complexes (62) where crystal field splitting leads to partial lifting of the five-fold degeneracy of transition metal (TM) d states into t2g and eg degenerate states. The interaction of these 14PDF Image | Investigation of metal-insulator transition in magnetron sputtered samarium nickelate thin films
PDF Search Title:
Investigation of metal-insulator transition in magnetron sputtered samarium nickelate thin filmsOriginal File Name Searched:
Bilewska_Investigation_of_metal_insulator_transition_in_magnetron_sputtered_samarium.pdfDIY PDF Search: Google It | Yahoo | Bing
Sulfur Deposition on Carbon Nanofibers using Supercritical CO2 Sulfur Deposition on Carbon Nanofibers using Supercritical CO2. Gamma sulfur also known as mother of pearl sulfur and nacreous sulfur... More Info
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |