Investigation of the new piezoelectric system (1−x)Bi(MgTi)0.5O3–xPbTiO3

Temperature dependence of piezoelectric properties of high-TC Bi(Mg1/2Ti1/2)O3–PbTiO3

“…According to literature, the piezoelectric properties of BMT-PT depend strongly on processing route. [13][14][15] BMT-PT can be obtained with high d 33 ͑225 pC/N͒ and large dielectric breakdown field using hot isostatic pressing. 13 Conventional processing leads to problems with respect to high conductivity 14,15 and low dielectric breakdown strength ͑5 kV/mm͒.…”

“…[13][14][15] BMT-PT can be obtained with high d 33 ͑225 pC/N͒ and large dielectric breakdown field using hot isostatic pressing. 13 Conventional processing leads to problems with respect to high conductivity 14,15 and low dielectric breakdown strength ͑5 kV/mm͒. 14 The piezoelectric coefficient ͑small signal d 33 = 166 pC/ N͒ is lower when using the one-step conventional process without employing MgTiO 3 as a precursor.…”

“…MgTiO 3 was first synthesized as a precur-sor at 1400°C for 4 h using reagent graded oxide precursors 13,15 and then mixed with PbO ͑99.9%, Alfa Aesar͒, TiO 2 ͑99.9%, Alfa Aesar͒, and Bi 2 O 3 ͑99.975%, Alfa Aesar͒ according to the stoichiometric formulas of each composition. These powder mixtures were ball milled in ethanol for 12 h. Calcination at 850°C for 5 h was then followed by renewed ball milling for another 12 h. Calcined powders were uniaxially pressed into pellets with a diameter of 10 mm and thickness of ϳ1 mm, and then hydrostatically compacted at 200 MPa.…”

“…[1][2][3] The operating temperature of piezoelectric ceramics is generally limited to one-half of the Curie point ͑T C ͒ due to loss of polarization, typically at temperatures lower than 200°C ͓e.g., 150°C for the conventional piezoelectric materials based on the Pb͑Zr 1−x Ti x ͒O 3 ͑PZT͔͒ with a Curie temperature, T C = 386°C. 4 After excellent piezoelectric properties for ͑1 − x͒BiScO 3 -xPbTiO 3 ͑BS-PT͒ near the morphotropic phase boundary ͑MPB͒ ͑x = 0.64͒ were reported ͑piezoelectric coefficient, d 33 = 460 pC/ N, planar coupling coefficient, k p = 0.56, and T C = 450°C͒ recently, 5,6 the discovery of several promising high temperature piezoelectric materials with high performance followed in the general BiMeO 3 -PbTiO 3 system, [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] where Me can be a single cation of valency +3 ͑e.g., Sc 3+ and Fe 3+ ͒ or a mixture of cations with an average valence of +3 ͑e.g., Mg 1/2 Ti 1/2 and Ni 2/3 Nb 1/3 ͒. It has been proposed that the Bi substitution plays an unusual role of considerable enhancement of both Curie temperature ͑T C ͒ and tetragonality ͑c / a͒, which results from a strong coupling between Pb/Bi cations and B-site cations of strong ferroelectric activity, such as Ti, Zn, and Fe.…”

“…Hence, most recent studies have been focusing on nonscandium perovskites. [12][13][14][15][16][17][18][19][20][21][22][23][24] In fact, possible new compositions in BiMeO 3 -PbTiO 3 -based systems are plenty, because B-site Me of BiMeO 3 could be any combination, which gives an average valence of +3. According to the currently available literature, however, the design of BiMeO 3 -PbTiO 3 piezoelectrics faces a significant challenge in that only few systems form a MPB with PbTiO 3 .…”