Characterization of Yttria-Stabilized Zirconia Thin Films Prepared by Radio Frequency Magnetron Sputtering for a Combustion Control Oxygen Sensor

Abstract

8 mol %-yttria-stabilized zirconia (YSZ) thin films as an oxygen ion conductor were deposited by radio frequency magnetron sputtering, and the oxygen gas sensing properties of YSZ were investigated using the structure of SiO 2 substrate/Ni-NiO/Pt/YSZ/Pt. X-ray diffractometry was employed to study the structure of YSZ and Ni-NiO films, and energy dispersion X-ray was used to investigate the composition of Ni-NiO thin films. The gas-sensing test was carried out for a SiO 2 /Ni-NiO/Pt/YSZ/Pt film structure exposed to oxygen-controlled environments. The steady-state electromotive force (EMF) values were measured as a function of oxygen partial pressure (p O2 ; 1.013 ϫ 10 3 to 1.013 ϫ 10 5 Pa) and operating temperature (573 to 973 K). The fabricated gas sensor cells showed good oxygen sensing properties at the temperature range from 673 to 773 K. However, the sensors were unstable at the operational temperatures above 873 K possibly due to the enhanced interdiffusion of the materials in the multilayer. Also the operation of the sensor at temperatures below 573 K was not good because the temperature was not sufficient to cause ionic conduction in the cell. At the optimum temperature range, the experimental EMF values measured as a function of oxygen partial pressure were close to the theoretically calculated EMF values.

Design and fabrication of dual-functional microcapsules containing phase change material core and zirconium oxide shell with fluorescent characteristics

“…As an important ceramic compound, zirconium oxide (ZrO 2 ) not only has outstanding physical properties such as high hardness, excellent thermal and chemical stabilities, and low thermal expansion coefficient but also demonstrates a functional diversity in catalytic activity, biocompatibility, optical and semiconductive characteristics, and photoelectric conversion property [31,32]. Such a multifunctional compound has found wide applications in structure ceramics [33], catalytic carriers [34], fuel cell [35], photocatalysis [36], and sensors [37], and also shows great application potential in electronics and optics [38,39]. If the PCMs are encapsulated with a ZrO 2 wall material, the resulting microencapsulated PCMs will not only gain a significant enhancement in mechanical strength but also obtain a multifunctional effectiveness.…”

Influence of the crystal structure on the physical properties of monoclinic ZrO2 nanocrystals

“…being thermally stable and having a high dielectric constant and useful optical and catalytic properties) that have led to it being used in many materials [1][2][3][4][5][6][7][8][9][10][11][12][13]. The magnetic properties of ZrO 2 have recently received significant attention because researchers wish to identify the principles involved in the mechanism that leads to the magnetic properties and to create multifunctional materials with these magnetic properties [34][35][36][37][38][39][40][41].…”

“…owing to its interesting optical, catalytic, dielectric and mechanical properties. Therefore, it has a wide range of applications in several technological fields [1][2][3][4][5][6][7][8][9][10][11]. ZrO 2 has several crystalline phases such as monoclinic, tetragonal and cubic phases, and the attractive functional properties of ZrO 2 depend on its crystalline phase [12,13].…”

Formation of autonomous ion sensors based on ion insertion-type materials

“…Indeed in the pristine configuration of such electrodes, a thin selective membrane was directly deposited on an electronic conductor allowing planar configurations and easy integration. Basically, the sensing device can easily be miniaturized by means of various thin film elaboration techniques such as screen printing [4,5], Pulsed Laser Deposition [6,7], e-beam evaporation [8], RF Sputtering [9] or polymeric membrane casting for the materials incorporation. However, while the ionic equilibrium between the solid and the solution was well defined, poor definition of the electronic transfer equilibrium at the membrane/solid contact interface led to badly defined electrode potential, which drifted with time.…”