scholarly journals METAL–INSULATOR TRANSITION IN 3D QUANTUM PERCOLATION

2008 ◽  
Vol 22 (29) ◽  
pp. 5217-5227 ◽  
Author(s):  
IGOR TRAVĚNEC
Keyword(s):  
Geometric Mean ◽  
Finite Size ◽  
Universality Class ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Mobility Edge ◽  
Metal Insulator ◽  
The Difference ◽  
Transition Study ◽  
Energy Plane

We present the metal–insulator transition study of a quantum site percolation model on simple cubic lattice. Transfer matrix method is used to calculate transport properties — Landauer conductance — for the binary distribution of energies. We calculate the mobility edge in disorder (ratio of insulating sites) — energy plane in detail and we find the extremal critical disorder somewhat closer to the classical percolation threshold than formerly reported. We calculate the critical exponent ν along the mobility edge and find it constant and equal to the one of 3D Anderson model, confirming common universality class. Possible exception is the center of the conduction band, where either the single-parameter scaling is not valid anymore, or finite size effects are immense. One of the reasons for such statement is the difference between results from arithmetic and geometric averaging of conductance at special energies. Only the geometric mean yields zero critical disorder in band center, which was theoretically predicted.

Ion-beam-induced metal-insulator transition inYBa2Cu3O7−δ: A mobility edge

1989 ◽  
Vol 39 (16) ◽  
pp. 11599-11602 ◽  
Author(s):  
J. M. Valles ◽  
A. E. White ◽  
K. T. Short ◽  
R. C. Dynes ◽  
J. P. Garno ◽  
...  
Keyword(s):  
Ion Beam ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Mobility Edge ◽  
Metal Insulator

Change of universality class of metal–insulator transition due to magnetic ordering

1999 ◽  
Vol 85 (8) ◽  
pp. 5332-5334 ◽  
Author(s):  
N. A. de Oliveira ◽  
M. V. Tovar Costa ◽  
A. Troper ◽  
Gloria M. Japiassú ◽  
M. A. Continentino
Keyword(s):  
Magnetic Ordering ◽  
Universality Class ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator

Effect of Co3+ Ion on Metal-Insulator Transition in (La0.1Ca0.9)(Mn1-xCox)O3

1998 ◽  
Vol 547 ◽  
Author(s):  
Hideki Taguchi
Keyword(s):  
Rietveld Analysis ◽  
Insulator Transition ◽  
Ion Content ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Type Semiconductor ◽  
Orthorhombic Perovskite ◽  
The Difference ◽  
Perovskite Type ◽  
Metallic Region

AbstractOrthorhombic perovskite-type (La0.1Ca0.9)(Mn1-xCox)O3 was synthesized in the range 0.00 ≤ x ≤ 0.08. The Rietveld analysis indicates that the (Mn, Co)-O(1 and 2) distances are independent of the composition (x). Measurements of the electrical resistivity (ρ) and the Seebeck coefficient (α) indicate that (La0.1Ca0.9)(Mn1-xCox)O3 is an n-type semiconductor at the low temperature. At the high temperature, (La0.1Ca0.9)(Mn1-xCox)O3 exhibits a metal-insulator transition in the range 0.0 ≤ x ≤ 0.04. The metal-insulator transition temperature (Tt) increases with increasing the Co3+ ion content, while dρ/dT in the metallic region decreases with increasing the Co3+ ion content. The variation of Ea and T+ is explained by the difference in the electronegativity between Mn and Co atoms. The variation of dρ/dT in the metallic region is explained by the increase in the collective o bond.

scholarly journals Giant magnetoimpedance near a metal–insulator transition: Study of Fe in a V2O3 matrix

2000 ◽  
Vol 77 (17) ◽  
pp. 2725-2727 ◽  
Author(s):  
Sangeetá Kale ◽  
S. E. Lofland ◽  
S. M. Bhagat ◽  
Litty Sebastian ◽  
K. Ramesha ◽  
...  
Keyword(s):  
Insulator Transition ◽  
Giant Magnetoimpedance ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Transition Study

scholarly journals Structures and Properties of New Organic Conductors: BEDT-TTF, BEST and BETS Salts of the HOC2H4SO3− Anion

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 775
Author(s):  
Hiroki Akutsu ◽  
Yuta Koyama ◽  
Scott S. Turner ◽  
Keigo Furuta ◽  
Yasuhiro Nakazawa
Keyword(s):  
Charge Transfer ◽  
Organic Conductors ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Structures And Properties ◽  
The Difference

New bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)-, bis(ethylenediseleno)tetrathiafulvalene (BEST)- and bis(ethylenedithio)tetraselenafulvalene (BETS)-based organic charge-transfer (CT) salts—α-(BEDT-TTF)3(HOC2H4SO3)2 (1), β-(BEST)3(HOC2H4SO3)2·H2O (2) and α-(BETS)2(HOC2H4SO3)·H2O (3)—have been prepared. Salts 1 and 2 show semiconducting behaviour. Salt 3, which is almost isostructural to α-(BETS)2I3, shows metallic behaviour down to 70 K and then shows a broader metal–insulator transition than that of α-(BETS)2I3. The reason for the difference in behaviour is estimated by the comparison of the Madelung energies of the full set of patterns of possible donor’s charge-ordered and anion’s disordered states.

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