Thermodynamics of the Charge-Density-Wave Transition in Blue Bronze

Brill, J. W.; Chung, Max; Kuo, Y. K.; Zhan, Xiaowen; Figueroa, E.; Mozurkewich, George

doi:10.1103/physrevlett.74.1182

Cited by 45 publications

(45 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Again, the robustness of this value suggests that at least most of the latent heat is being captured in the specific heat measurements. If this transition is due to formation of a charge-densitywave, as suggested by Baumberger, et al [15], then the expected entropy change ∆S ~ ∆γ·T c (assuming that fluctuation effects are negligible [19,21,23]), giving ∆γ /R ~ 6 x 10 -3 K -1 , i.e. the change in γ at the transition is significantly larger than its low temperature value, consistent with the low conductivity and/or lower dimensionality of the low temperature state.…”

mentioning

confidence: 94%

“…In this work, we use both relaxation-time calorimetry [18] and ac-calorimetry [19][20][21] to examine the specific heat anomalies at the phase transitions. While ac-calorimetry may also not be a reliable method for obtaining latent heats [19,22], we have compared the specific heat peaks obtained under different experimental conditions and for different samples to conclude that most of the latent heat is in fact appearing in this peak, in agreement with the conclusion of Reference [14].…”

mentioning

confidence: 99%

“…We used ac-calorimetry [19][20][21] to measure the specific heat of flux grown pure and Sr-substituted single crystals. For the pure materials, measurements were made on two crystals of masses 0.36 and 0.40 mg. For the Sr-substituted samples, the masses were 0.43 mg (x=0.15) and 0.54 mg (x=0.58).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Specific heat of (Ca1−xSrx)3Ru2O7 single crystals

Varadarajan

Saito

Durairaj

et al. 2007

Solid State Communications

View full text Add to dashboard Cite

We have measured the specific heat of crystals of (Ca 1-x Sr x ) 3 Ru 2 O 7 using ac-and relaxation-time calorimetry. Special emphasis was placed on the characterization of the Néel (T N =56 K) and structural (T c = 48 K) phase transitions in the pure, x=0 material.While the latter is believed to be first order, detailed measurements under different experimental conditions suggest that all the latent heat (with L ~ 0.3 R) is being captured in a broadened peak in the effective heat capacity. The specific heat has a mean-fieldlike step at T N , but its magntitude (∆c P ~ R) is too large to be associated with a conventional itinerant electron (e.g. spin-density-wave) antiferromagnetic transition, while its entropy is too small to be associated with full ordering of localized spins. The T N transition broadens with Sr substitution while its magnitude decreases slowly. On the other hand, the entropy change associated with the T c transition decreases rapidly with Sr substitution and is not observable for our x=0.58 sample. PACS: 71.27.+a, 75.40.Cx, 65.40 The spin-structure of the double-layer, n =2, compounds have been especially unusual. In the pure strontium (i.e. x=1) salt, there is no resulting long range spin order at ambient pressure, but longitudinal strain can induce a ferromagnetic state [5,10]. In the pure calcium (x=0) salt, the spins order ferromagnetically within the bilayers, but the interlayer (c-axis) interactions are predominantly antiferromagnetic, leading to a Néel transition at T N = 56 K with spin polarization along the b-axis [6,[11][12][13]. With further cooling, the spin polarization rotates within the plane toward the a-axis [13,14]. There is a second, more unusual, phase transition at T c = 48 K; here all components of the susceptibility drop abruptly upon cooling through T c [11,14], which has been suggested to be due to formation of a charge-density-wave [15], while the lattice contracts along c by [3,11,20]. All crystals studied were characterized by single crystal or powder x-ray diffraction, EDS and TEM,indicating good crystal quality with no impurities or intergrowths or significant clustering of strontium ions. Magnetic and transport properties were measured using a Quantum Design MPMS XL 7T magnetometer. (Since the shape of all crystals studied in this work is essentially cubic, the demagnetizing factor for all samples and all three principal crystallographic axes is expected to be the same, and is not included in our the susceptibility is almost isotropic in the ab-plane (suggesting that the RuO 6 octahedra are almost "untilted", as in the pure Sr compound) with peaks in M at T p ~ 50 K followed by weak minima (T~ 40 K) and relatively high susceptibilities at lower temperatures.Only small anomalies are observed in the resistance at these temperatures, and the shape of the magnetic anomalies [4] suggests that spin ordering is complex but incomplete. A more complete discussion of the substitution-dependence of the resistance and magnetization, including their field dependence...

show abstract

mentioning

confidence: 94%

mentioning

confidence: 99%

See 1 more Smart Citation

Specific heat of (Ca1−xSrx)3Ru2O7 single crystals

Varadarajan

Saito

Durairaj

et al. 2007

Solid State Communications

View full text Add to dashboard Cite

show abstract

“…Theoretical arguments and experimental observations that justify this conclusion in the case of charge density wave systems can be found in the literature [17,18,19,20]. Appendix C contains a brief, heuristic argument for the nature of the melting transition in the counterion system.…”

Section: "Melting" Of the Counterion Latticementioning

confidence: 99%

“…The attraction between rods in such a state has been extensively explored by Ha and Liu, [2,15,16]. The melting transition is continuous and can be shown to be in the universality class of the three-dimensional XY model; see, e.g., [17,18,19,20]. A brief review of the arguments leading to this conclusion appears in an appendix.…”

Section: Introductionmentioning

confidence: 99%

Cohesive energy, stability, and structural transitions in polyelectrolyte bundles

Rudnick

Jasnow²

2003

Phys. Rev. E

View full text Add to dashboard Cite

A lattice of uniformly charged, infinitesimally thin, rods decorated with an ordered array of counterions exhibits anomalous behavior as the spacing between the rods is varied. In particular, the counterion lattice undergoes a sequence of structural shearing, or "tilting," phase transformations as the spacing between the rods decreases. The potential implications of this behavior with respect to the packaging of biologically relevant polyelectrolytic molecules are commented upon.

show abstract

Elastic and Thermal Properties of Low-Dimensional Conductors

Brill

1996

Physics and Chemistry of Low-Dimensional Inorganic Conductors

View full text Add to dashboard Cite

Thermodynamics of the Charge-Density-Wave Transition in Blue Bronze

Cited by 45 publications

References 31 publications

Specific heat of (Ca1−xSrx)3Ru2O7 single crystals

Specific heat of (Ca1−xSrx)3Ru2O7 single crystals

Cohesive energy, stability, and structural transitions in polyelectrolyte bundles

Elastic and Thermal Properties of Low-Dimensional Conductors

Contact Info

Product

Resources

About