Thermal Characterization and Crystal Structure of an Electrorheological Material — Complex Strontium Titanate

Abstract

A new type of anhydrous complex strontium titanate (STO) electrorheological fluid (ERF) material is obtained, which demonstrates a good electrorheological (ER) character even at lower applied electric field. Its shear stress is about 8~kPa at electric field of 2.4 kV/mm. The current density is only 1.6 μA/cm2 leaking through the fluids. Some additive in our samples prevents sedimentation. The shear stresses vary only slightly in a wide temperature range. The thermal characteristics of the solid phase STO including the heat capacity and thermal stability were investigated. The value of the activation energy of crystallization was derived to be about 100 kJ/mole. The crystal structure of Y-doped STO was refined by the Rietveld method. Y 3+ substitutes for Sr 2+ in the 1(a) position of space group Pm3m.