Effect of additives on the electrical properties of a (Ba0.92Sr0.08)TiO3-based positive temperature coefficient resistor

Densification and micro-structure evolution of BaTiO3/ZrO2 composites

“…The piezoelectric ceramic materials such as BaTiO 3 , (Ba,Sr)TiO 3 and Pb(Zr,Ti)O 3 (PZT) have many technical applications as actuators and sensors [1][2][3].…”

Effects of TiO2 and SiO2 additions on phase formation, microstructures and PTCR characteristics of Sb-doped barium strontium titanate ceramics

“…Cheng et al 15 have added varying amounts of AST to Sb-BST, which allows a direct comparison with results obtained here for 1 mol% TiO 2 + 3 mol% SiO 2 . 1 The room temperature resistivities, ρ RT , for Sb-BST + AST were reportedly higher, of the order 10 2 -10 3 cm, depending on total additive content, compared to 8-14 cm here for TiO 2 + SiO 2 . The maximum resistivities on heating to higher temperatures, ρ max , were also higher for the AST system, giving a ρ max /ρ RT ratios as high as 10 5.6 compared to ∼10 4 for the more simple TiO 2 + SiO 2 additives in this work.…”

“…1 Low resistivity at room temperature and a strong PTCR effect are both critical parameters for device applications. Barium titanate, BaTiO 3 , is the basis for most PTCR materials, however, unmodified BaTiO 3 is an insulator which shows a high intrinsic resistivity of more than 10 10 cm at room temperature, when prepared in an oxidizing atmosphere, and no PTCR effect can be observed.…”

“…Nb 5+ , Ta 5+ ) substituting on Ti 4+ sites of the perovskite ABO 3 lattice. 1 Heywang first proposed that the PTCR effect was dependent on electron traps (acceptor states) along grain boundaries resulting in electron depletion layers and Schottky barriers. 4 Jonker subsequently explained the absence of any PTCR effect below the Curie temperature (T C ) in terms of spontaneous polarisation of ferroelectric domains.…”

Preparation and electrical properties of Ni/(Ba,Sr)TiO3 PTC composite with low resistivity

“…The interfacial reaction should be investigated as much as possible so that the processing can be controlled and electrical properties can be optimized. However, in the reference [5], metal was just regarded as low-resistance phase. Though in the limited literature [1,3,6], metal-ceramics (M-C) contact was considered as Ohmic contact, the details of the M-C interface were not considered.…”