초록 ▼

A piezoelectric ceramic for acoustic surface wave devices which consists essentially of a solid solution of the ternary system Pb(Sna1-a3-PbTiO3-PbZrO3 having a composition showing a phase transition between a ferroelectric rhombohedral low temperature phase (FR(LT)) and a ferroelectric rohombohedra

A piezoelectric ceramic for acoustic surface wave devices which consists essentially of a solid solution of the ternary system Pb(Sna1-a3-PbTiO3-PbZrO3 having a composition showing a phase transition between a ferroelectric rhombohedral low temperature phase (FR(LT)) and a ferroelectric rohombohedral high temperature phase (FR(HT)) at a temperature within the range from -20°C. to +80°C. The solid solution consists essentially of a main component expressed by the formula: xPb(Sna1-a3-yPbTiO3-zPbZrO3 where in x+y+z=1.00, ¼≤a2 and, if necessary, further contains at least one element selected, from magnesium and chromium in oxide form in respective amounts of 0.05 to 5.0 wt % when respectively converted into MgO and Cr2O3.

대표청구항 ▼

An acoustic surface wave device comprising: a piezoelectric ceramic wafer consisting essentially of a solid solution of the ternary system Pb(Sn½Sb½) O3-PbTiO3-PbZrO3 having a composition showing a phase transition between a ferroelectric rhombohedral low temperature phase (FR(LT)) and a ferroelectr

An acoustic surface wave device comprising: a piezoelectric ceramic wafer consisting essentially of a solid solution of the ternary system Pb(Sn½Sb½) O3-PbTiO3-PbZrO3 having a composition showing a phase transition between a ferroelectric rhombohedral low temperature phase (FR(LT)) and a ferroelectric rhombohedral high temperature phase (FR(HT)) at a temperature within the range from -20°C. to +80°C.; and at least one electromechanical transducing means for converting an electrical signal into acoustic surface waves and vise versa, said transducing means comprising interdigital transducing electrodes coupled to a surface of said piezoelectric ceramic wafer at a transducing region thereof, said composition consisting essentially of a main component expressed by the general formula: xPb(Sn½Sb½)O3-yPbTiO3-zPbZrO3 wherein, x+y+z=1.00, and an additive consisting of manganese in oxide form in an amount of 0.05 to 5.0 wt% in the form of MnO2, said main component having a composition in the compositional area defined by points A, B, C, D, E1, F1 and G in FIG. 4, the sets of mol fractions of the three components at said points being as follows: ________________________________ -x y z ________________________________ A 0.01 0.44 0.55 B 0.01 0.04 0.95 C 0.04 0.01 0.95 D 0.15 0.01 0.84 E1 0.25 0.01 0.74 F1 0.25 0.25 0.50 G 0.15 0.35 0.50. ________________________________ An acoustic surface wave device comprising: a piezoelectric ceramic wafer consisting essentially of a solid solution of the ternary system Pb(Sn½Sb½)O3-PbTiO3-PbZrO3 having a composition showing a phase transition between a ferroelectric rhombohedral low temperature phase (FR(LT)) and a ferroelectric rhombohedral high temperature phase (RR(HT)) at a temperature within the range from -20°0 C. to 80°; and at least one electrochemical transducing means for converting an electrical signal into acoustic surface waves and vise versa, said transducing means comprising interdigital transducing electrodes coupled to a surface of said piezoelectric ceramic wafer at a transducing region thereof, said composition consisting essentially of a main component expressed by the general formula: xPb(Sn½Sb⅓)O3-yPbTiO3-zPbZrO3 wherein, x+y=z=1.00, and additives consisting of manganese in oxide form in an amount of 0.05 to 5.0 wt% in the form of MnO2 and at least one element selected from the group consisting of magnesium and chromium in oxide form in respective amounts of 0.05 to 5.0 wt% in the form of MgO and Cr2O3, said main component having a composition in the compositional area defined by points A, B, C, D, E1, F1 and G in FIG. 4, the sets of mol fractions of the three components at said points being as follows: ________________________________ -x y z ________________________________ A 0.01 0.44 0.55 B 0.01 0.04 0.95 C 0.04 0.01 0.95 D 0.15 0.01 0.84 E1 0.25 0.01 0.74 F1 0.25 0.25 0.50 G 0.15 0.35 0.50. ________________________________