dc.contributor | Goethe Univ Frankfurt | |
dc.contributor | Universidade Estadual Paulista (Unesp) | |
dc.contributor | RIKEN | |
dc.date.accessioned | 2014-12-03T13:11:25Z | |
dc.date.available | 2014-12-03T13:11:25Z | |
dc.date.created | 2014-12-03T13:11:25Z | |
dc.date.issued | 2014-01-10 | |
dc.identifier | Physical Review B. College Pk: Amer Physical Soc, v. 89, n. 4, 5 p., 2014. | |
dc.identifier | 1098-0121 | |
dc.identifier | http://hdl.handle.net/11449/113118 | |
dc.identifier | 10.1103/PhysRevB.89.045113 | |
dc.identifier | WOS:000332207600005 | |
dc.identifier | WOS000332207600005.pdf | |
dc.description.abstract | The organic charge-transfer salt EtMe3P[Pd(dmit)(2)](2) is a quasi-two-dimensional Mott insulator with localized spins S = 1/2 residing on a distorted triangular lattice. Here we report measurements of the uniaxial thermal expansion coefficients alpha(i) along the in-plane i = a and c axis as well as along the out-of-plane b axis for temperatures 1.4 K <= T <= 200 K. Particular attention is paid to the lattice effects around the phase transition at T-VBS = 25 K into a low-temperature valence-bond-solid phase and the paramagnetic regime above where effects of short-range antiferromagnetic correlations can be expected. The salient results of our study include (i) the observation of strongly anisotropic lattice distortions accompanying the formation of the valence-bond-solid phase, and (ii) a distinct anomaly in the thermal expansion coefficients in the paramagnetic regime around 40 K. Our results demonstrate that upon cooling through T-VBS the in-plane c axis, along which the valence bonds form, contracts while the second in-plane a axis elongates by the same relative amount. Surprisingly, the dominant effect is observed for the out-of-plane b axis which shrinks significantly upon cooling through T-VBS. The pronounced anomaly in alpha(i) around 40 K is attributed to short-range magnetic correlations. It is argued that the position of this maximum, relative to that in the magnetic susceptibility around 70 K, speaks in favor of a more anisotropic triangular-lattice scenario for this compound than previously thought. | |
dc.language | eng | |
dc.publisher | Amer Physical Soc | |
dc.relation | Physical Review B | |
dc.relation | 1,604 | |
dc.rights | Acesso restrito | |
dc.source | Web of Science | |
dc.title | Lattice effects in the quasi-two-dimensional valence-bond-solid Mott insulator EtMe3P[Pd(dmit)(2)](2) | |
dc.type | Artículos de revistas | |