The thermal stability and structural characteristics for gate stack structure of HfO2 dielectrics deposited by atomic-layer deposition (ALD) were investigated. chemical state the films in relation to film thickness postannealing temperature examined x-ray diffraction photoelectron spectroscopy. An interfacial layer hafnium silicate with an amorphous was grown on oxidized Si substrate at initial growth stage. are closely affected depended films. 45 Å thick changed into a polycrystalline after...

For 0.95(Na0.5K0.5)NbO3–0.05BaTiO3 (0.95NKN-0.05BT) ceramics sintered at 1040–1075°C, abnormal grain growth occurred but the size decreased when sintering temperature exceeded 1075°C. The dielectric constant (ϵ3T∕ϵ3), electromechanical coupling factor (kp), and piezoelectric (d33) were considerably increased with increasing relative density size. Evaporation of Na2O deteriorated properties by decreasing resistivity. To minimize evaporation, specimens muffled 0.95NKN-0.05BT powders during...

Mixtures of zinc metatitanate and rutile (ZnTiO 3 + x TiO 2 , where = 0‐0.5) have been prepared via the conventional mixed‐oxide method. Centrifugal planetary milling with zirconia beads 1 mm in diameter produced very fine powders (mean particle size 0.2 µm), which allowed synthesis ZnTiO sintering at temperatures <945°C, is decomposition temperature . Sintering mixtures was enhanced further by addition B O Densities >94% theoretical density attained for specimens that were sintered...

The orthorhombic structure of (Na 0.5 K )NbO 3 (NKN) ceramics was maintained when ZnO added. NKN have a porous microstructure and dissolve they are exposed to water. However, as added, dense developed deliquescence not observed. mechanical quality factor ( Q m ) coercive field E c increased with the addition ZnO, indicating that acted hardener in ceramics. dielectric constant ε T / o ), piezoelectric d 33 electromechanical coupling k p small amount which might be due increase density. good...

A dielectric ceramic comprised of (Zn 1‐ x Mg )TiO 3 ( = 0 to 0.5) with low sintering temperature and promising microwave properties was prepared by applying a semichemical synthesis route microbeads milling technique. X‐ray diffractometry thermal analyses results indicated that the phase stability region hexagonal (Zn,Mg)TiO extended higher temperatures as amount magnesium increased. The in this system exhibited significant dependence on conditions, especially near decomposition...

The integration of electrochromic (EC) and thermochromic (TC) systems is important for realizingmultifunctional smart windows, which can adaptively control light transmittance solar energy in response to diverse external stimuli. In this study, we developed an all-solid-state multifunctional window, tungsten oxide (WO3)-based EC vanadium (VO2)-based TC cells were integrated into a single device. hybrid the WO3-based layer modulates optical transmission electrical voltage, while VO2-based...

Amorphous KNbO3 (KN) films were grown on a TiN/SiO2/Si substrate to synthesize KN memristor as potential artificial synapse. The Pt/KN/TiN exhibited typical and reliable bipolar switching behavior with multiple resistance levels. It also showed the transmission properties of biological synapse, good conductance modulation linearity. Moreover, can emulate various synaptic plasticity characteristics including short-term plasticity, long-term spike-rate dependent paired-pulse facilitation,...

When a small amount of CuO was added to (Na 0.5 K )NbO 3 (NKN) ceramics sintered at 960°C for 2 h, dense microstructure with increased grains developed, probably due liquid‐phase sintering. The Curie temperature slightly when exceeded 1.5 mol%. Cu 2+ ion considered have replaced the Nb 5+ and acted as hardener, which E c Q m values NKN ceramics. High piezoelectric properties k p =0.37, =844, ɛ T /ɛ 0 =229 were obtained from specimen containing mol% h.

The crystal structure of (1−x)(Na0.5K0.5)NbO3-xCaTiO3 ceramics began to change from orthorhombic tetragonal at x≥0.03, then became a morphotropic phase boundary in which both the orthogonal and phases coexisted 0.03<x<0.07, was converted x≥0.07. Curie temperature decreased with increasing x specimen relaxor x≥0.03. A dense microstructure large grains developed 0.04<x<0.07 due liquid sintering. relative density, grain size, considerably influenced piezoelectric...

Zn 2 SiO 4 ceramics synthesized by the conventional solid‐state method exhibited a low Q × f value, possibly due to formation of ZnO second phase. However, with small reduction from ceramics, phase disappeared and grain growth occurred Si‐rich liquid Specimens large size an improved value. In particular, nominal composition 1.8 3.8 sintered at 1300°C microwave dielectric properties ɛ r =6.6, =147 000 GHz, τ =−22 ppm/°C.

MgSiO 3 ceramics were synthesized and their microwave dielectric properties investigated. The Mg 2 SiO 4 phase was formed at temperatures lower than 1200°C, while the orthorhombic started to form by reaction of in specimen fired 1200°C. structure transformed from monoclinic when sintering temperature exceeded 1400°C. A dense microstructure developed for specimens sintered above 1350°C. excellent ɛ r =6.7, Q × f =121 200 GHz, τ =−17 ppm/°C obtained 1380°C 13 h.

BaCu(B 2 O 5 ) ceramics were synthesized and their microwave dielectric properties investigated. phase was formed at 700°C melted above 850°C. The ceramic sintered 810°C had a constant (ɛ r of 7.4, quality factor ( Q × f 50 000 GHz temperature coefficient resonance frequency (τ −32 ppm/°C. As the low melting good properties, it can be used as low‐temperature sintering aid for materials co‐fired application. When added to Ba(Zn 1/3 Nb 2/3 )O 3 (BZN) ceramic, BZN well even existed liquid...

(1− x )(Na 0.5 K )NbO 3 – LiNbO [(1− )NKN– LN] ceramics were produced by the conventional solid‐state sintering method, and their microstructure piezoelectric properties investigated. The formation of liquid phase 6 Li 4 Nb 10 O 30 second that observed in LN was explained evaporation Na 2 during sintering. A morphotropic boundary (MPB) specimens with 0.05< <0.08. Promising obtained for =0.07. Therefore, this 0.93NKN–0.07LN ceramic further investigated found to be influenced relative...

A bio-realistic artificial synapse integrated with a nanogenerator (NG), which can be used in neuromorphic systems, is demonstrated for self-powered biomedical devices this study. Biocompatible amorphous (Na0.5K0.5)NbO3 (NKN) films are grown on TiN/polyimide substrates to synthesize NKN memristors use as synapses. Various synaptic functions realized memristors, driven by pulse generator and an NG. The plasticity of the memristor results from oxygen vacancy movements changes shape filaments....

(Na 0.5 K )NbO 3 (NKN) and BaTiO (BT) ceramics form a homogeneous solid solution. The relative density of the (1- x )NKN– BT solutions significantly decreased when ≤0.07. Although 0.95NKN–0.05BT ceramic was very low, it had high d 33 value 134 pC/N. MnO 2 added to improve piezoelectric properties by enhancing their sinterability. addition increased specimens, as well improving properties. 0.9 mol % showed good k p =0.31, =194 pC/N ε T / 0 = 800.

Hard piezoelectrics with high dielectric and piezoelectric constants are used for high‐power applications. However, the sintering temperature of these ceramics is high, around 1200°C, restricting usage cheap base metal electrodes in fabrication multi‐layer components. This study investigates effect CuO ZnO on a hard piezoelectric, APC 841, which MnO 2 ‐ Nb O 5 ‐modified PZT. The addition decreased through formation liquid phase. properties CuO‐added sintered at ≤950°C were lower than desired...

The sintering temperature of 0.95(Na 0.5 K )NbO 3 –0.05BaTiO (NKN–BT) ceramics needs to be decreased below 1000°C prevent Na 2 O evaporation, which can cause difficulties in poling and may eventually degrade their piezoelectric properties. NKN–BT containing CuO were well sintered at 950°C with grain growth. Poling was easy for all specimens. Densification growth explained by the formation a liquid phase. addition improved properties increasing size density. High d 33 =230 pC/N, k p =37%, ɛ T...

Formation process and microwave dielectric properties of the R 2 V O 7 (R=Ba, Sr, Ca) ceramics were investigated. Transient RV 6 phases, which formed at 300°∼500°C by reaction RCO 3 5 , interacted with remnant to form homogeneous triclinic phases 600°–700°C. The Sr Ca sintered 1000° 950°C, respectively, for 10 h showed a dense microstructure ɛ r =10.4–12.1, Q × f =15 200–19 520 GHz, τ =−30.9–34.8 ppm/°C. However, Ba ceramic was well 900°C it good =10.1, =51 630 =−26.5