TY - JOUR
T1 - Crystal structure and microwave dielectric properties of (1 - X)ZnTa 2O 6-xTiO 2 ceramics
AU - Park, Jeong Hyun
AU - Nahm, Sahn
AU - Park, Jae Gwan
N1 - Funding Information:
This research was supported by a Grant from the Center for Advanced Materials Processing (CAMP) of the Knowledge Economy Frontier R&D Program funded by the Ministry of Knowledge Economy (MKE), Republic of Korea , and also by the KIST Institutional Program 2E23220 .
PY - 2012/10/5
Y1 - 2012/10/5
N2 - The crystal structural variations of (1 - x)ZnTa 2O 6-xTiO 2 ceramics sintered at 1250 °C for 2 h were investigated, and the relationship of these variations with the microwave dielectric properties were studied. Four types of crystal structures were identified with increasing x: tri-α-PbO 2, α-PbO 2, trirutile, and rutile. For x ≤ 0.2, single-phase solid solutions of the tri-α-PbO 2 structure were formed, whereas for x = 0.4, a mixture of two solid solution phases based on the α-PbO 2 and trirutile structures was obtained. For x = 0.5, a single phase of ZnTiTa 2O 8 with the trirutile structure was obtained, and for x ≥ 0.6, the ceramics formed single-phase solid solutions of the rutile structure. The microwave dielectric properties of the ceramics were changed by the crystal structural transitions: for x < 0.4, the phases of the tri-α-PbO 2 or α-PbO 2 structures exhibited ZnTa 2O 6-like dielectric behavior, while for x ≥ 0.4, the phases of the trirutile or rutile structure exhibited more TiO 2(rutile)-like behaviors as x increased. The ZnTiTa 2O 8 (x = 0.5) ceramics had a dielectric constant (k) of 46.2, a quality factor (Q × f) of 36,700 GHz, and a temperature coefficient of the resonant frequency (τ f) of +74 ppm/°C.
AB - The crystal structural variations of (1 - x)ZnTa 2O 6-xTiO 2 ceramics sintered at 1250 °C for 2 h were investigated, and the relationship of these variations with the microwave dielectric properties were studied. Four types of crystal structures were identified with increasing x: tri-α-PbO 2, α-PbO 2, trirutile, and rutile. For x ≤ 0.2, single-phase solid solutions of the tri-α-PbO 2 structure were formed, whereas for x = 0.4, a mixture of two solid solution phases based on the α-PbO 2 and trirutile structures was obtained. For x = 0.5, a single phase of ZnTiTa 2O 8 with the trirutile structure was obtained, and for x ≥ 0.6, the ceramics formed single-phase solid solutions of the rutile structure. The microwave dielectric properties of the ceramics were changed by the crystal structural transitions: for x < 0.4, the phases of the tri-α-PbO 2 or α-PbO 2 structures exhibited ZnTa 2O 6-like dielectric behavior, while for x ≥ 0.4, the phases of the trirutile or rutile structure exhibited more TiO 2(rutile)-like behaviors as x increased. The ZnTiTa 2O 8 (x = 0.5) ceramics had a dielectric constant (k) of 46.2, a quality factor (Q × f) of 36,700 GHz, and a temperature coefficient of the resonant frequency (τ f) of +74 ppm/°C.
KW - Crystal structure
KW - Dielectric response
KW - Sintering
KW - TEM
KW - X-ray diffraction
UR - http://www.scopus.com/inward/record.url?scp=84862772810&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2012.05.065
DO - 10.1016/j.jallcom.2012.05.065
M3 - Article
AN - SCOPUS:84862772810
VL - 537
SP - 221
EP - 226
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
ER -