Influence of sintering additives on densification and Li+ conductivity of Al doped Li7La3Zr2O12 lithium garnet

Al–LLZ with 1 wt% of Li4SiO4 added and sintered at 1200 °C was found to be relatively dense which enhances the total (bulk + grain-boundary) Li+ conductivity by reducing the grain-boundary contribution.

Structural and electrical properties of Ti doped α-Fe2O3

In this work we have analyzed the effects of Ti doping on structural and electrical properties of ?-Fe2O3. When the amount of added Ti (5 wt.%TiO2) was within the solubility degree and XRD, SEM and EDS analysis revealed a homogenous hematite structure, with lattice parameters a= 5.03719(3) ?, c=13.7484(1) ? slightly increased due to incorporation of Ti into the rhombohedral hematite lattice. Higher amounts of Ti (10 wt.%TiO2) resulted in the formation of pseudobrookite, besides hematite, confirmed by SEM and EDS analysis. Studies of electric properties in the temperature range 25-225oC at different frequencies (100 - 1Mz) showed that Ti doping improved electrical conductivity. Impedance analysis was performed using an equivalent circuit, showing one relaxation process and suggesting dominant grain boundary contribution.

Thermally Activated Relaxation and Hysteretic Internal Friction in Ultrafine Grained Copper

Temperature and amplitude dependent internal friction (TDIF and ADIF) in ultrafine-grained copper (99.95% Cu) specimens processed by equal channel angular extrusion by route BC in 1, 4, and 8 passes and then subjected to annealing is investigated by means of dynamical mechanical analyzer DMA Q800 in the temperature range from -100 to 550 °C, amplitude range from 10-6 to 10-3, and frequency range from 0.05 to 100 Hz. Two IF peaks were registered and explained by structural relaxation due to the recrystallisation process and by thermally activated grain boundary relaxation with broad distribution of relaxation times. Increase in amplitude dependent damping in ultrafine-grained copper is due to dislocation but not grain boundary contribution.