Influence of zinc on electrical and microstructural properties of CaCu3Ti4O12 ceramics prepared by sol–gel process

Microstructure and electrical properties of Sc2O3-doped ZnO–Bi2O3-based varistor ceramics

Study of biocompatibility of medical grade high nitrogen nickel-free austenitic stainless steel in vitro

Microstructure and electrical properties of Y(NO3)3·6H2O-doped ZnO-Bi2O3-based varistor ceramics

With the rapid development of science and technology, the functionalization of structural materials, and the structurization of functional materials are attracting increasing attention in the scientific and engineering fields. The development of multi-functional materials and structures (MFMS), at the micro- and nano-scale levels, has grown rapidly due to the requirement of increasing safety margins for all infrastructure, biomedical and engineering elements. Multi-functional material systems are capable of performing multiple 'primary' functions, simultaneously or sequentially in time, and are specially designed to improve system performance via a reduction in the redundancy between sub-system materials and functions. Materials having special structures can exhibit multi-functional properties. For example, shape-memory alloys can act as actuators as well as sensors, and the aim of composite materials is to exploit each aspect's advantages; plus their synergistic effect. The current collection of peer-reviewed papers focuses on multi-functional materials and structures for various engineering applications, and makes a valuable contribution to the literature on the subject.

Multi-functional materials and structures II : selected, peer reviewed papers from the 2nd International Conference on Multi-functional Materials and Structures, October 9-12, 2009, Qingdao, Shandong, P.R. China

La2O3-doped ZnO-Bi2O3-based varistor ceramics were obtained by a solid reaction route, and the microstructure and electrical properties of the varistor ceramics were studied in this paper. The results showed with addition of 0-1.00mol% La2O3, La2O3-doped ZnO-based varistor ceramics were prepared in this paper with the voltage gradient of 77-503V/mm, the nonlinear coefficient of 2.4-36.8, and the leakage current of 0.09-494μA. The results also showed with addition of 0.08mol% La2O3, La2O3-doped ZnO-based varistor ceramics exhibit comparatively ideal comprehensive electrical properties. Such as the threshold voltage was 320V/mm, the nonlinear coefficient was 36.8 and the leakage current was 0.29μA. The doping of La2O3 affects the form and decomposition of the pyrochlore.

Microstructure and Electrical Properties of La2O3-Doped ZnO-Bi2O3 Based Varistor Ceramics

We have established the micro-magnetic field on the surfaces of 316L stainless steel and NiTi alloy through the magnetization process of sol–gel prepared TiO2 thin film with the powder of SrFe12O19. The nano-sized with brown color of SrFe12O19 powder was verified by transmission electron microscope. By using X-ray diffraction, surface roughometer, and corrosion experimental test, the deposited thin film can decrease the etching of body fluid as well as prevent the hazardous Ni ions released from the metal. Moreover, with evaluation of dynamic cruor time test and blood platelets adhesion test, we found the micro-magnetic field of the thin film can improve the blood compatibility.

Effects of micro-magnetic field at the surface of 316L and NiTi alloy on blood compatibility.

TiO2 thin film containing SrFe12O19 powders on the surface of 316L stainless steel and NiTi alloy was prepared through sol-gel method and micro-magnetic field was established by the magnetization process applied on the coating. The coating film was characterized by x-ray diffraction (XRD) and the surface morphology of the coating was observed by scanning electron microscope (SEM). This blood compatibility thin film was evaluated by dynamic cruor time of blood test.The results show that dynamic cruor time of blood is prolonged by the micro-magnetic field of the thin film, indicating improved blood compatibility.

Micro-Magnetic Field at the Surface of Surgical Materials for Biocompatibility Improvement

The Ge doped Mn3CuN powder was synthesized using gas-solid reaction method with manganese, copper, germanium powders and N2 gas as raw material. The phase constitute of the as-prepared powder was characterized using X-ray diffraction (XRD). The intrinsic and macro thermal expansion coefficients of the powder were measured by in-situ X-ray diffraction at different temperatures and TMA, respectively. The crystal structure of the powders was analyzed using Rietveld refinement method. The results show that the pure Mn3(Cu0.5Ge0.5)N powder can be prepared via the gas-solid method at 850 °C. The crystal structures of Mn3(Cu0.5Ge0.5)N and Mn3CuN both have the antiperovskite structures. The intrinsic and macro thermal expansion coefficient of Mn3(Cu0.5Ge0.5)N powder is-16.8×10-6K-1 and-17×10-6K-1, respectively. The temperature range with negative thermal expansion is from-80 °C to 50 °C.

Xiao Nong Cheng

Papers

Microstructure and Electrical Properties of La2O3-Doped ZnO-Bi2O3 Based Varistor Ceramics

Effects of micro-magnetic field at the surface of 316L and NiTi alloy on blood compatibility.

Micro-Magnetic Field at the Surface of Surgical Materials for Biocompatibility Improvement

Crystal Structure and Thermal Expansion of Ge-Doped Mn3CuN