Surface-modified Zn0.5Ti0.5NbO4 particles filled polytetrafluoroethylene composite with extremely low dielectric loss and stable temperature dependence

Abstract

Polymer-ceramic composites are widely applied in microwave substrate materials due to the excellent dielectric properties and simple preparation process recently. Polytetrafluoroethylene-based (PTFE) composites filled with Zn0.5Ti0.5NbO4 (ZTN) ceramic particles were fabricated by hot-pressing. The particles were modified by C14H19F13O3Si to enhance the interface compatibility between PTFE and ZTN powders, which was characterized by X-ray photoelectron spectroscopy (XPS) and contact angle. The surface characteristic of particles transformed into hydrophobicity and tight microstructure as well as better dielectric properties were obtained after the surface modification. The microstructure, dielectric, thermal, mechanical properties, and water absorption of the composites concerning ZTN content were investigated. Modified ZTN/PTFE composites with 50 vol% ZTN particles exhibit excellent dielectric properties with a high dielectric constant of 8.3, an extremely low dielectric loss of 0.00055 at 7 GHz, and a stable temperature coefficient of the dielectric constant of −12.2 ppm/°C. All the properties show modified ZTN particles filled PTFE composite is the potential material for microwave substrate application.

Investigation on the improvement of microwave dielectric properties of plasma-prepared fluoropolymer-coated CaTiO3-filled PTFE composites

“…It has been proved that surface treatment with C 14 H 19 F 13 O 3 Si (F8261) can significantly improve the surface properties of ICAMIM-2023 Journal of Physics: Conference Series 2720 (2024) 012045 IOP Publishing doi:10.1088/1742-6596/2720/1/012045 2 ceramics, making them exhibit strong hydrophobicity. The modified ceramic surface, because the molecular structure (carbon-fluorine bonding) is similar to that of PTFE, can be a better bridge to establish with the PTFE and promote the formation of a compact structure [5][6][7] . However, these treatment methods are mostly chemical methods, which have the defects of complicated operation, harsh reaction conditions, low efficiency, and producing a large amount of waste organic solvents.…”

Microwave Frequency Offset Induced by Subsurface Damage in Abrasive-Machined Semiconductor Ceramic Waveguide

“…It is traditionally believed that the reasons for a frequency offset are the thermal deformation of materials and machining errors affecting device dimensions. Many studies have focused on synthesizing ceramic materials with low or even near-zero temperature coefficients [14][15][16][17]. Moreover, adequate studies have been conducted on the influence of errors in dimensions on waveguide components.…”

Effect of Coating Shell on High-Frequency Polarization Loss of Core-Shell Filler Dielectric Composites: An Alternating-Field Polarization Phase-Field Simulation of BN@SiO2/PTFE Composite

“…High dielectric loss in high filler content composite, which may originate from the dielectric mismatch between the filler and the matrix, is one of the current hot issues and has been discussed widely [6][7][8]. Recently, filler coating has been regarded as an effective way to eliminate dielectric mismatch [9][10][11][12]. Silicon dioxide (SiO 2 ) has a lower dielectric constant than BN, and the SiO 2 coating might influence the high-frequency dielectric loss of the BN/PTFE composite [13][14][15].…”