Sahn Nahm

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

Zn 2 SiO 4 ceramics synthesized by the conventional solid‐state method exhibited a low Q × f value, possibly due to the formation of a ZnO second phase. However, with a small ZnO reduction from the Zn 2 SiO 4 ceramics, the ZnO second phase disappeared and grain growth occurred due to the formation of a Si‐rich liquid phase. Specimens with a large grain size exhibited an improved Q × f value. In particular, the ceramics with nominal composition Zn 1.8 SiO 3.8 sintered at 1300°C exhibited improved

MgSiO 3 ceramics were synthesized and their microwave dielectric properties were investigated. The Mg 2 SiO 4 phase was formed at temperatures lower than 1200°C, while the orthorhombic MgSiO 3 phase started to form by the reaction of SiO 2 and Mg 2 SiO 4 in the specimen fired at 1200°C. The structure of the MgSiO 3 ceramics was transformed from orthorhombic to monoclinic when the sintering temperature exceeded 1400°C. A dense microstructure was developed for the specimens sintered at above 1350°

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

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 the usage of cheap base metal electrodes in fabrication of multi‐layer components. This study investigates the effect of CuO and ZnO on the sintering temperature of a hard piezoelectric, APC 841, which is a MnO 2 ‐ and Nb 2 O 5 ‐modified PZT. The addition of CuO decreased the sintering temperature throu

Re 3 Ga 5 O 12 (Re: Nd, Sm, Eu, Dy, Yb, and Y) garnet ceramics were synthesized and their microwave dielectric properties were investigated for advanced substrate materials in microwave integrated circuits. The Re 3 Ga 5 O 12 ceramics sintered at 1350°–1500°C had a high‐quality factor ( Q × f ) ranging from 40 000 to 192 173 GHz and a low‐dielectric constant (ɛ r ) of between 11.5 and 12.5. They also exhibited a relatively stable temperature coefficient of resonant frequency (τ f ) in the range

Formation process and microwave dielectric properties of the R 2 V 2 O 7 (R=Ba, Sr, and Ca) ceramics were investigated. Transient RV 2 O 6 phases, which were formed at 300°∼500°C by the reaction of RCO 3 and V 2 O 5 , interacted with remnant RCO 3 to form the homogeneous triclinic R 2 V 2 O 7 phases at 600°–700°C. The Sr 2 V 2 O 7 and Ca 2 V 2 O 7 ceramics sintered at 1000° and 950°C, respectively, for 10 h showed a dense microstructure with the microwave dielectric properties of ɛ r =10.4–12.1,

The sintering temperature of 0.95(Na 0.5 K 0.5 )NbO 3 –0.05BaTiO 3 (NKN–BT) ceramics needs to be decreased below 1000°C to prevent Na 2 O evaporation, which can cause difficulties in poling and may eventually degrade their piezoelectric properties. NKN–BT ceramics containing CuO were well sintered at 950°C with grain growth. Poling was easy for all specimens. Densification and grain growth were explained by the formation of a liquid phase. The addition of CuO improved the piezoelectric propertie

MnO 2 was added to 0.75Pb(Zr 0.47 Ti 0.53 )O 3 –0.25Pb(Zn 1/3 Nb 2/3 )O 3 (0.75PZT–0.25PZN) ceramics in order to make a high‐power piezoelectric material. The Mn 4+ ion produced a defect dipole consisting of an Mn 4+ ion and an oxygen vacancy that transformed the 0.75PZT–0.25PZN ceramics into hard materials. The Q m value significantly increased with the addition of MnO 2 and reached a value of 1680 for the 1.5 mol% MnO 2 ‐added 0.75PZT–0.25PZN ceramic. Moreover, this specimen exhibited a high k

The sintering temperature of the LiAlSiO 4 (LAS) ceramics, which exhibited the microwave dielectric properties of ε r = 4.8, Q × f = 36 000GHz, and τ f =8.0 ppm/°C, decreased below 960°C when B 2 O 3 was added. The B 2 O 3 ‐related liquid phase was formed and assisted the densification of the LAS ceramics at low temperatures. The average grain size of the specimen sintered at 950°C increased with the addition of B 2 O 3 but decreased when B 2 O 3 exceeded 12.0 mol%, probably due to the presence