Transport and magnetic properties of a MottHubbard system whose bandwidth and band filling are both controllable: R{sub 1{minus}x}Ca{sub x}TiO{sub 3+y/2}
Abstract
Transport and magnetic properties of R{sub 1{minus}x}Ca{sub x}TiO{sub 3+y/2} have been systematically investigated varying the oneelectron bandwidth (W) and the band filling (n=1{minus}{delta}), which can be controlled by the Rdependent lattice distortion and by the Ca content x and/or oxygen offstoichiometry y ({delta}=x+y), respectively. The end compound RTiO{sub 3} is a 3d{sup 1} MottHubbard insulator and its chargegap magnitude increases with decreasing ionic radius of R, i.e., an increase of electron correlation (U/W) in proportion with (U/W){minus}(U/W){sub c}, where (U/W){sub c} is the critical value for the (hypothetical) n=1 Mott transition. Such a Mott insulator is transformed to a correlated metal by substitution of R with Ca (hole doping), and the nominal hole concentration required for the insulatormetal transition ({delta}{sub c}) increases in proportion with (U/W){minus}(U/W){sub c}. Concerning magnetism, RTiO{sub 3} with R=La, Pr, Nd, and Sm, shows the antiferromagnetic ordering and its N{acute e}el temperature (T{sub N}) decreases with smaller R. T{sub N} also decreases with Ca doping, but remains finite up to the metalinsulator phase boundary. On the basis of these results, electronic phase diagrams are derived for a series of titanates as an electroncorrelated system with changes of two parameters, i.e., the strength of electron correlation andmore »
 Authors:

 Department of Applied Physics, University of Tokyo, Tokyo 113 (Japan)
 Publication Date:
 OSTI Identifier:
 543824
 Resource Type:
 Journal Article
 Journal Name:
 Physical Review, B: Condensed Matter
 Additional Journal Information:
 Journal Volume: 56; Journal Issue: 16; Other Information: PBD: Oct 1997
 Country of Publication:
 United States
 Language:
 English
 Subject:
 36 MATERIALS SCIENCE; LANTHANUM OXIDES; MAGNETIC PROPERTIES; ELECTRIC CONDUCTIVITY; PRASEODYMIUM OXIDES; NEODYMIUM OXIDES; SAMARIUM OXIDES; CALCIUM OXIDES; TITANIUM OXIDES; BAND THEORY; STOICHIOMETRY; ANTIFERROMAGNETIC MATERIALS; NEEL TEMPERATURE; HOLES; ELECTRON CORRELATION
Citation Formats
Katsufuji, T, Taguchi, Y, and Tokura, Y. Transport and magnetic properties of a MottHubbard system whose bandwidth and band filling are both controllable: R{sub 1{minus}x}Ca{sub x}TiO{sub 3+y/2}. United States: N. p., 1997.
Web. doi:10.1103/PhysRevB.56.10145.
Katsufuji, T, Taguchi, Y, & Tokura, Y. Transport and magnetic properties of a MottHubbard system whose bandwidth and band filling are both controllable: R{sub 1{minus}x}Ca{sub x}TiO{sub 3+y/2}. United States. doi:10.1103/PhysRevB.56.10145.
Katsufuji, T, Taguchi, Y, and Tokura, Y. Wed .
"Transport and magnetic properties of a MottHubbard system whose bandwidth and band filling are both controllable: R{sub 1{minus}x}Ca{sub x}TiO{sub 3+y/2}". United States. doi:10.1103/PhysRevB.56.10145.
@article{osti_543824,
title = {Transport and magnetic properties of a MottHubbard system whose bandwidth and band filling are both controllable: R{sub 1{minus}x}Ca{sub x}TiO{sub 3+y/2}},
author = {Katsufuji, T and Taguchi, Y and Tokura, Y},
abstractNote = {Transport and magnetic properties of R{sub 1{minus}x}Ca{sub x}TiO{sub 3+y/2} have been systematically investigated varying the oneelectron bandwidth (W) and the band filling (n=1{minus}{delta}), which can be controlled by the Rdependent lattice distortion and by the Ca content x and/or oxygen offstoichiometry y ({delta}=x+y), respectively. The end compound RTiO{sub 3} is a 3d{sup 1} MottHubbard insulator and its chargegap magnitude increases with decreasing ionic radius of R, i.e., an increase of electron correlation (U/W) in proportion with (U/W){minus}(U/W){sub c}, where (U/W){sub c} is the critical value for the (hypothetical) n=1 Mott transition. Such a Mott insulator is transformed to a correlated metal by substitution of R with Ca (hole doping), and the nominal hole concentration required for the insulatormetal transition ({delta}{sub c}) increases in proportion with (U/W){minus}(U/W){sub c}. Concerning magnetism, RTiO{sub 3} with R=La, Pr, Nd, and Sm, shows the antiferromagnetic ordering and its N{acute e}el temperature (T{sub N}) decreases with smaller R. T{sub N} also decreases with Ca doping, but remains finite up to the metalinsulator phase boundary. On the basis of these results, electronic phase diagrams are derived for a series of titanates as an electroncorrelated system with changes of two parameters, i.e., the strength of electron correlation and band filling. Possible origins of the insulating state with finite hole doping are also discussed in terms of the kinetic energy of doped carriers in the MottHubbard insulator. {copyright} {ital 1997} {ital The American Physical Society}},
doi = {10.1103/PhysRevB.56.10145},
journal = {Physical Review, B: Condensed Matter},
number = 16,
volume = 56,
place = {United States},
year = {1997},
month = {10}
}