Effect of NaCl on the microstructure and electrical properties of K0.5Na0.5NbO3 ceramics prepared by cold sintering process

Composition segregation and grain growth in (K0.5Na0.5)NbO3 piezoceramics prepared by two‐step cold sintering process

“…For the application of underwater acoustic sensors, KNN ceramics require a low dielectric constant. 24 Moreover, the evolution of dielectric constants is quite similar to the d 33 evolution shown in Figure 9A. This result demonstrates that higher pressure can be conductive to obtain higher dielectric constants, and the enhanced d 33 should result from the enhancement of dielectric constants.…”

Elevating electrical properties of (K, Na)NbO3ceramics via cold sintering process and post‐annealing

“…[7][8][9]40,41 The chemical and volume ch pany ceramization of the polymer during documented in several studies. CSP, 26,39 these values for the relative dielectric constant and piezoelectric coefficient are highest whereas the preparing temperature is lowest, as shown in Figure 6E,F. As mentioned above, the lengthening of cold sintering dwell time can improve the density of KNN ceramics.…”

“…Preceramic polycarbosilane polymers are commonly used as precursors to make ceramic fibers 10,39 and ceramic matrix. [7][8][9]40,41 The chemical and volume changes that accompany ceramization of the polymer during pyrolysis have been documented in several studies.…”

Cold sintering of microwave dielectric ceramics and devices

“…CSCCs are a series of ceramics or ceramic composites that can be densified at ultralow temperatures < 200 °C by the cold sintering process (CSP) [3,[42][43][44][45][46][47][48][49], which enables not only co-firing with base-metal electrodes [3,50,51] but also PCBs [52] and polymers [43,53]. Along with CSCCs for RF applications, cold sintering has also been employed to densify ferroelectrics [54][55][56][57][58], piezoelectrics [59][60][61][62][63], thermoelectrics [64], semiconductors [65][66][67][68][69][70], electrolytes [71][72][73][74][75], cathodes [76,77] and oxides [78][79][80][81][82], which are widely used in many applications, Fig. 1.…”

“…More recently, dense BT nanoceramics (ρ r ~ 92-95%, grain size ~ 75-150 nm) were successfully cold sintered in a single step at 300 °C for 12 h at 520 MPa with the aid of a molten hydroxide flux (NaOH:KOH = 1:1) [55]. Piezoelectric ceramics, such as lead zirconate titanate (Pb(Zr,Ti)O 3 , PZT), potassium-sodium niobate (K 0.5 Na 0.5 NbO 3 , KNN) and sodium bismuth titanate (Na 0.5 Bi 0.5 TiO 3 ), have been successfully densified by cold sintering with the help of transient liquid-phase (Pb(NO 3 ) 2 solution for PZT, NaCl aqueous solution for KNN and Bi(NO 3 ) 3 / NaOH/TiO 2 suspension for NBT [59][60][61][62][63]. Semiconductor V 2 O 5 as well as V 2 O 5 -poly (3,4-ethylenedioxythiophene) poly(styrene sulfonate) (PEDOT:PSS) composites have been cold sintered at 120 °C [66]; the electrical conductivity (4.8 × 10 −4 S/cm at 25 °C), activation energy (0.25 eV at 25 °C) and Seebeck coefficient (− 990 μV/K at 50 °C) of cold-sintered V 2 O 5 were comparable to conventionally sintered samples and were further increased by the addition of 1-2 vol% PEDOT:PSS.…”