D max rc x ray diffractometer

The system of 0.985(K_1/2Na_1/2)O₃-0.015Ba(Cu_1/3Nb_2/3)O₃ was synthesized from the oxides of >99% purity by the conventional solid-state route. The powders of K₂CO₃, Na₂CO₃, Nb₂O₅, BaCO₃, and CuO (all obtained from Sigma Aldrich) were mixed for 6–48 h in a polypropylene jar with zirconia balls. This mixture of powders was dried and calcined at the temperature range of 800–950 ^oC for 3 h. Calcined powders were milled for 6–48 h, dried and pressed into disks under the pressure of 10 MPa and sintered in the range of 1070~1120 ^oC for 2–10 h. The giant grain was obtained when the powders were ball-milled for 6–18 h (both 1^st and 2^nd ball-milling processes). The crystal structure of specimens was examined using Rigaku D/max-RC X-ray diffractometer. The microstructure was observed under a scanning electron microscope (SEM, JSM-5800; JEOL CO., Tokyo, Japan). The samples were poled in silicone oil at 120 ^oC by applying a dc field of 2–4 kV/mm for 30 min. All the electrical measurements were conducted after aging the samples for 24 h. The piezoelectric and dielectric properties were determined using a piezo d₃₃ meter (Micro-Epsilon Channel Product DT-3300) and an impedance analyzer (4294A, Agilent Technologies, Santa Clara, CA, USA).