Heisenberg exchange enhancement by orbital relaxation in cuprate compounds

被引:73
作者
vanOosten, AB [1 ]
Broer, R [1 ]
Nieuwpoort, WC [1 ]
机构
[1] UNIV GRONINGEN,CTR MAT SCI,NL-9747 AG GRONINGEN,NETHERLANDS
关键词
D O I
10.1016/0009-2614(96)00498-8
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
We calculate the Heisenberg exchange J in the quasi-2D antiferromagnetic cuprates La2CuO4, YBa2Cu3O6, Nd2CuO4 and Sr2CuO2Cl2. We apply all-electron (MC)SCF and non-orthogonal CI calculations to [Cu2O11](18-), [Cu2O9](14-), [Cu2O7](10-) and [Cu2O7Cl4](14-) clusters in a model charge embedding. The (MC)SCF tripler and singlet ground states are well characterized by Cu2+ (d(x2-y2)) and O2-. The antiferromagnetic exchange is strongly enhanced by admiring relaxed (MC)SCF triplet and singlet excited states, in which a single electron is transferred from the central O ion to Cu. We ascribe this effect to orbital relaxation in the charge transfer component of the wavefunction. Close agreement with experiment is obtained.
引用
收藏
页码:207 / 212
页数:6
相关论文
共 35 条
[1]   MAGNETIC DYNAMICS OF LA2CUO4 AND LA2-XBAXCUO4 [J].
AEPPLI, G ;
HAYDEN, SM ;
MOOK, HA ;
FISK, Z ;
CHEONG, SW ;
RYTZ, D ;
REMEIKA, JP ;
ESPINOSA, GP ;
COOPER, AS .
PHYSICAL REVIEW LETTERS, 1989, 62 (17) :2052-2055
[2]   NEW APPROACH TO THE THEORY OF SUPEREXCHANGE INTERACTIONS [J].
ANDERSON, PW .
PHYSICAL REVIEW, 1959, 115 (01) :2-13
[3]   POSSIBLE HIGH-TC SUPERCONDUCTIVITY IN THE BA-LA-CU-O SYSTEM [J].
BEDNORZ, JG ;
MULLER, KA .
ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER, 1986, 64 (02) :189-193
[4]   BROKEN ORBITAL SYMMETRY AND THE DESCRIPTION OF VALENCE HOLE STATES IN THE TETRAHEDRAL [CRO4]2- ANION [J].
BROER, R ;
NIEUWPOORT, WC .
THEORETICA CHIMICA ACTA, 1988, 73 (5-6) :405-418
[5]   ABINITIO STUDY OF THE SINGLET TRIPLET SPLITTING IN SIMPLE-MODELS FOR DICHLORO-BRIDGED AND DIFLUORO-BRIDGED CU(II) DIMERS [J].
BROER, R ;
MAASKANT, WJA .
CHEMICAL PHYSICS, 1986, 102 (1-2) :103-111
[6]  
BROER R, 1991, REV SOLID STATE SCI, V5, P79
[7]  
BURGHGRAEF H, 1990, THESIS U GRONINGEN
[8]   Origin of magnetic coupling in La2CuO4 [J].
Casanovas, J ;
Rubio, J ;
Illas, F .
PHYSICAL REVIEW B, 1996, 53 (02) :945-951
[9]  
Dunning T.H., 1977, Modern Theoretical Chemistry, V3
[10]   SPECTROSCOPIC EVIDENCE FOR STRONGLY CORRELATED ELECTRONIC STATES IN LA-SR-CU AND Y-BA-CU OXIDES [J].
FUJIMORI, A ;
TAKAYAMAMUROMACHI, E ;
UCHIDA, Y ;
OKAI, B .
PHYSICAL REVIEW B, 1987, 35 (16) :8814-8817