Study on electric modulus, complex modulus and conductivity properties of Nb/Sm, Gd doped barium titanate-lithium ferrite ceramic composites

Softening of bulk modulus and negative Poisson ratio in barium titanate ceramic near the Curie point

Substantial softening in the bulk modulus (a factor of five) and a negative Poisson ratio (-0.25) have been observed via broadband viscoelastic spectroscopy in the vicinity of the Curie point of a barium titanate ceramic. These effects were observed under electrical short-circuit conditions at low deformation frequencies. Softening was less in an electric open circuit or at higher frequencies. ...

The Effect of Aging on Nano-Hardness and Modulus of Elasticity of Four Types of Composites: An in-vitro Study

Introduction: Resin composites are an important part of restorative treatment in modern dentistry. There are many trademarks available in Iran market and physico-chemical properties of many of these resin composites are not evaluated yet. This study was carried out to evaluate the physico-chemical properties of four available resin composites and also to assess the effect of aging on their prop...

Aging of CKN: modulus versus conductivity analysis.

It was recently reported that the electrical modulus peaks narrows upon annealing of the ionic system CKN [Paluch et al., Phys. Rev. Lett. 110, 015702 (2013)], which was interpreted as providing evidence of dynamic heterogeneity of this glass. The present analysis of the same data in terms of the ac conductivity shows no shape changes, however. We discuss the relation between both findings and ...

Effect of re-oxidation firing on PTCR properties of Sm-doped barium titanate ceramics

The effect of reduction and re-oxidation firing on the PTCR properties of Sm-doped barium titanate ceramics was investigated for the application in multilayered PTC thermistors. The lattice parameters a, and c decreases monotonically with increasing oxygen concentration in the re-oxidation atmosphere, which seems to be related with an electrostatic Coulomb interaction between an oxygen vacancy ...

Dielectric Permittivity and Electric Modulus in Bi2Ti4O11