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2. Mott-Peierls phase in deuterated copper-DCNQI systems: a comprehensive study of longitudinal and transverse conductivity and ageing effectsMarko Pinterić, Tomislav Vuletić, Martin Lončarić, Konstantin Petukhov, Boris Gorshunov, Jost Ulrich von Schütz, Silvija Tomić, Martin Dressel, 2003, izvirni znanstveni članek Opis: Transport and low-frequency optical reflection measurements (180-380 GHz) are reported for the quasi-three-dimensional conducting alloy ▫$Cu[(2,5(CH_3)_2-DCNQI)_{0.70}(2,5(CD_3)_2-DCNQI)_{0.30}]_2$▫ between room temperature and 35 K. The optical properties of the system are strongly anisotropic. It is metallic down to 60 K where a Mott-Peierls phase transition occurs. While the transverse conductivity remains practically unchanged, the longitudinal conductivity abruptly drops at the phase transition. Comparing our latest results with previous dc data and measurements of the microwave conductivity also reported here, we find indications of an ageing effect in these samples.
Ključne besede: optical reflection measurements, organic conductors, microwave conductivity, phase transitions metal-insulator, ageing effect
Objavljeno: 01.06.2012; Ogledov: 805; Prenosov: 48
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3. Influence of internal disorder on the superconducting state in the organic layered superconductor [kappa]-(BEDT-TTF)[sub]2Cu[N(CN)[sub]2]BrMarko Pinterić, Silvija Tomić, Mladen Prester, Đuro Drobac, Kazumi Maki, 2002, izvirni znanstveni članek Opis: We report high-sensitivity AC susceptibility measurements of the penetration depth in the Meissner state of the layered organic superconductor ▫$kappa$▫-(BEDT-TTF)▫$_2$▫Cu[N(CN)▫$_2$▫]Br. We have studied nominally pure single crystals from the two different syntheses and employed controlled cooling procedures in order to minimize intrinsic remnant disorder at low temperatures associated with the glass transition, caused by ordering of the ethylene moieties in BEDT-TTF molecule at ▫$T_{text{G}}$▫ = 75°K. We find that the optimal cooling procedures (slow cooling of -0.2°K/h or annealing for 3 days in the region of ▫$T_{text{G}}$▫) needed to establish the ground state, depend critically on the sample origin indicating different relaxationtimes of terminal ethylene groups. We show that, in the ground state, the behavior observed for nominally pure single crystals from both syntheses is consistent with unconventional $d$-wave order parameter. The in-plane penetration depth ▫$lambda_{text{in}}(T)$▫ is strongly linear, whereas the out-of-plane component ▫$lambda_{text{out}}(T)$▫ varies as ▫$T^2$▫. In contrast, the behavior of single crystals with long relaxation times observed after slow (-0.2°K/h) cooling is as expected for a $d$-wave superconductor with impurities (textit{i.e.} ▫$lambda_{text{in}}(T) proptolambda_{text{out}}(T) propto T^2$▫) or might be also reasonably welldescribed by the ▫$s$▫-wave model. Our results might reconcile the contradictory findings previously reported by different authors.
Ključne besede: solid state physics, organic superconductors, magnetic measurements
Objavljeno: 01.06.2012; Ogledov: 987; Prenosov: 22
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4. Electrodynamics in organic dimer insulators close to mott critical pointMarko Pinterić, David Rivas Góngora, Željko Rapljenović, Tomislav Ivek, Matija Čulo, B. Korin-Hamzić, Ognjen Milat, Branko Gumhalter, Predrag Lazić, Miriam Sanz Alonso, Weiwu Li, Andrej Pustogow, Guilherme Gorgen Lesseux, Martin Dressel, Silvija Tomić, 2018, izvirni znanstveni članek Ključne besede: strongly correlated systems, Mott insulators, quantum spin liquid, dielectric properties, vibrational properties, density functional theory
Objavljeno: 27.06.2018; Ogledov: 479; Prenosov: 218
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