{'fraction_non_alphanumeric': 0.05672268907563025, 'fraction_numerical': 0.06827731092436974, 'mean_word_length': 4.706586826347305, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Fracture Toughness and Electrical Properties of 0.975Bi(Na0.78K0.22)TiO3–0.025BiAlO3 Ceramics

0.975Bi(Na0.78K0.22)TiO3–0.025BiAlO3 ceramics were prepared by a conventional solid-state reaction. Their electric properties, such as P–E loops, S–E curve, and permittivity, were investigated and their fracture toughness was studied using a Vickers indentation test. Their density was 5.90 g/cm3, and their grains have an average size below 1 µm and a cubic morphology. The P–E hysteresis loops of Bi(Na,K)TiO3–BiAlO3 had a slightly pinched and well-saturated loop at 6 kV/mm, exhibiting a small remnant polarization (7.7 µC/cm2) and a large saturated polarization (40 µC/cm2). Little negative strain was observed in the reverse bias region. The small signal d33 was 120 pC/N and the large signal d33 was 500–600 pC/N. The fracture toughness of the above ceramics was calculated to be 2.877 MPa·m1/2 and compared with those of PZT- and KNN-based materials.