5 research outputs found
Control parameter for the glass transition of glycerol evidenced by the static-field-induced nonlinear response
International audienceBy studying a nonlinear susceptibility on supercooled glycerol, we show that applying a static field E st increases the glass transition temperature T g by an amount quadratic in E st. This has important consequences: (i) it reinforces the relation between the two paths put forward in the last years to unveil the dynamical correlation volume close to T g ; (ii) it clarifies the interpretation of nonlinear measurements; (iii) it yields a new control parameter of the glass transition, which paves the way for experiments deepening our understanding of glasses
High temperature phase transition studies and dielectric properties of Sr2SbMnO6
International audienceSr2SbMnO6 (SSMO) ceramics were, fabricated using the nanocrystalline powders obtained via molten salt synthesis (MSS) method. High temperature X-ray diffraction studies confirmed the structural phase transition (room temperature tetragonal (I4/mcm) to the cubic phase (Pm-3m)) temperature to be around 736K. The discontinuity in the phase transition indicated its first order nature reflecting the presence of ferroelectric-like distortions in SSMO prepared from MSS which seemed to be unique as it was not observed so far in the case of SSMO prepared using solid-state reaction method. The dielectric behavior of SSMO was studied in the 300-950 K temperature range at high frequencies (MHz range) in order to suppress the of space charge and related effects that dominate at such higher temperatures and mask the real phase transition
Unifying different interpretations of the nonlinear response in glass-forming liquids
This work aims at reconsidering several interpretations coexisting in the
recent literature concerning non-linear susceptibilities in supercooled
liquids. We present experimental results on glycerol and propylene carbonate
showing that the three independent cubic susceptibilities have very similar
frequency and temperature dependences, both for their amplitudes and phases.
This strongly suggests a unique physical mechanism responsible for the growth
of these non-linear susceptibilities. We show that the framework proposed by
two of us [BB, Phys. Rev. B 72, 064204 (2005)], where the growth of non-linear
susceptibilities is intimately related to the growth of "glassy domains",
accounts for all the salient experimental features. We then review several
complementary and/or alternative models, and show that the notion of
cooperatively rearranging glassy domains is a key (implicit or explicit)
ingredient to all of them. This paves the way for future experiments which
should deepen our understanding of glasses