Correlation between crystal structures and polar (ferroelectric) properties of hybrids of haloantimonates(iii) and halobismuthates(iii)

Halogenoantimonates(iii) and halogenobismuthates(iii) are a highly versatile class of organic–inorganic hybrid materials, applicable in optoelectronics and switchable dielectric devices.

Biocompatible/Biodegradable Electrowetting on Dielectric Microfluidic Chips with Fluorinated CTA/PLGA

One of the major hurdles in the development of biocompatible/biodegradable EWOD (Electrowetting-on-dielectric) devices is the biocompatibility of the dielectric and hydrophobic layers. In this study, we address this problem by using reactive ion etching (RIE) to prepare a super-hydrophobic film combining fluorinated cellulose triacetate (CTA) and poly (lactic-co-glycolic acid) (PLGA). The contact angle (CA) of water droplets on the proposed material is about 160°. X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) characterizations indicate that a slight increase in the surface roughness and the formation of CFx (C-F or CF2) bonds are responsible for the super-hydrophobic nature of the film. Alternating Current (AC) static electrowetting and droplet transportation experiments evidence that contact angle hysteresis and contact line pinning are greatly reduced by impregnating the CTA/PLGA film with silicon oil. Therefore, this improved film could provide a biocompatible alternative to the typical Teflon® or Cytop® films as a dielectric and hydrophobic layer.

Temperature compensation effects of TiO2 on Ca[(Li1/3Nb2/3)0.8Sn0.2]O3−δ microwave dielectric ceramic

The crystal structure and dielectric properties of TiO2-modified Ca[(Li[Formula: see text]Nb[Formula: see text])[Formula: see text]Sn[Formula: see text]]O[Formula: see text] microwave ceramics are investigated in the present paper. The crystal structure is probed by XRD patterns and their Rietveld refinement, results show that a single perovskite phase is formed in TiO2-modified Ca[(Li[Formula: see text]Nb[Formula: see text])[Formula: see text]Sn[Formula: see text]]O[Formula: see text] ceramics with the crystal structure belonging to the orthorhombic Pbnm 62 space group. Raman spectra results indicate that the [Formula: see text]-site order–disorder structure transition is a key point to the dielectric loss of TiO2-modified Ca[(Li[Formula: see text]Nb[Formula: see text])[Formula: see text]Sn[Formula: see text]]O[Formula: see text] ceramics at microwave frequencies. After properly modified by TiO2, the large negative temperature coefficient of Ca[(Li[Formula: see text]Nb[Formula: see text])[Formula: see text]Sn[Formula: see text]]O[Formula: see text] ceramic can be compensated and the optimal microwave dielectric properties can reach [Formula: see text] = 25.66, [Formula: see text] = 18,894 GHz and TCF = −6.3 ppm/[Formula: see text]C when sintered at 1170[Formula: see text]C for 2.5 h, which manifests itself for potential use in microwave dielectric devices for modern wireless communication.