Antiferromagnetic ordering of organic Mott insulator lambda-(BEDSe-TTF)(2)GaCl4

Article

关键词: CHARGE-TRANSFER SALTS;    BEDT-TTF;    PHYSICAL-PROPERTIES;    MAGNETIC-PROPERTIES;    CRYSTAL-STRUCTURE;    BAND-STRUCTURE;    PHASE-DIAGRAM;    BETS;    SUPERCONDUCTORS;    TRANSITION;   

DOI  :  10.1103/PhysRevB.106.045114

来源: SCIE

【 摘 要 】

The band structure and magnetic properties of organic charge-transfer salt lambda-(BEDSe-TTF)(2)GaCl4 [BEDSe-TTF: bis(ethylenediseleno)tetrathiafulvalene; abbreviated as lambda-BEDSe] are investigated. The re-ported crystal structure is confirmed using x-ray diffraction measurements, and the transfer integrals are calculated. The degree of electron correlation U/W (U: on-site Coulomb repulsion, W: bandwidth) of lambda-BEDSe is larger than one and comparable to that of the isostructural Mott insulator lambda-(ET)(2)GaCl4 (ET: bis(ethylenedithio)tetrathiafulvalene, abbreviated as lambda-ET), whereas the U/W of the superconducting salt lambda-(BETS)(2)GaCl4 [BETS: bis(ethylenedithio)tetraselenafulvalene] is smaller than one. C-13-NMR and mu SR measurements revealed that lambda-BEDSe undergoes an antiferromagnetic (AF) ordering below T-N = 22 K. In the AF state, discrete C-13-NMR spectra with a remaining central peak are observed, indicating the commensurate AF spin structure also observed in lambda-ET. The similarity of the structural and magnetic properties between lambda-BEDSe and lambda-ET suggests that both salts are in the same electronic phase, i.e., the physical properties of lambda-BEDSe can be understood by the universal phase diagram of bandwidth-controlled lambda-type organic conductors obtained by donor molecule substitution.

【 授权许可】

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