Table 1 Summary representing some of the relevant reports on the growth of single crystals via the SSCG method
Category | Formula | Seed | Growth conditions | Crystal size | Key parameters | Application | Refs. |
|---|---|---|---|---|---|---|---|
Pb-based piezoelectrics | PMN‒PT | (001) PMN–PT | Hot pressing in excess PbO (880‒900 °C, 30 min, 20 MPa), then annealing in air (1150 °C, 0‒10 h) | – | Increase of k with increase of PbO up to 3 vol.%; decrease of k with PbO larger than 3 vol.% | Transducers and actuators for military and medical application | [45] |
Undoped and Mn-doped PMN‒PT | BZT | Hot pressing to obtain ceramics, then annealing at high temperatures | (30 × 30 × 5) mm3 | KT3, d33, tan δ - 50% decrease, EC - 150% increase, and Qm - 500% increase compared to PMN‒PT ceramics | High-power piezoelectric transducers | [46] | |
PMN‒PT | BaTiO3 | Hot pressing to obtain ceramics, then annealing at high temperatures | > 1.5 inch (~ 38 mm) | Chemically homogeneous, high-density single crystal | – | [48] | |
BS–PMN–PT | (110) BZT | Annealing (1050 °C, 100 h) with PbO/Bi2O3 flux and embedded seed | 500–1000 μm | Good chemical stability, no migration of ions between the seed and the grown single crystal | Electromechanical devices operated at elevated temperatures | [49] | |
Mn‒PMN‒PZT | BZT | Heat treatment of pre-sintered ceramics with seed on top | (15 × 15 × 5) mm3 | TRT = 145 °C; EC = 6.3 kV/cm; k33 > 0.9; d33 = 850‒1100 pC/N | High-power piezoelectric applications (sonar transducers, medical ultrasonic devices, ultrasonic motors) | [8] | |
Pb-free piezoelectrics | KNN | (110) KTaO3 | Two-step sintering in hot press (975 °C, 2 h, 50 MPa, then 1100 °C, 100 h, 50 MPa) with K4CuNb8O23 as sintering aid and embedded seed | 1890 µm | Porosity and pore size significantly reduced (from 100 to 1‒2 µm) by hot pressing | Pb-free replacement for PZT piezoelectrics | [52] |
KNN‒BCuN | No seed | Sintering (1120 °C, 2 h) with CuO as sintering aid and BaCO3 to compensate for the Na+ loss | 1.3 cm | g33 = 131 × 10−3 Vm/N | Piezoelectric sensors and energy harvesting devices | [58] | |
(K0.45Na0.55)0.96Li0.04NbO3 | No seed | Sintering in air (1080 °C, 10 h) | (6 × 5 × 2) mm3 | TC = 432 °C; d33 = 689 pC/N; d*33 = 967 pm/V | High-performance Pb-free piezoelectrics | [59] | |
CaZrO3‒Na0.5K0.5NbO3 | No seed | Sintering in air (1090–1115 °C, 15 h) | 2 cm | TC = 391 °C; d33 = 488 pC/N | – | [60] | |
NBT‒BT‒KNN | (110) SrTiO3 | Sintering (800 °C, 50 h) with embedded seed | (6 × 6 × 8) mm3 | (001)-oriented NBT‒BT‒KNN: Smax = 0.57% and d*33 = 1050 pm/V at 7 kV/mm | Replacement for Pb-based piezoelectrics | [63] | |
NBT‒BT‒KNN | (110) SrTiO3 | Pre-sintering of ceramics (950 °C, 10 min), then annealing in air (900 °C, 30 h) with seed on top | (3 × 3 × 0.8) mm3 | ρ = 96.9%; Smax = 0.67% and d*33 = 1670 pm/V at 4 kV/mm | High-stroke actuator applications | [65] | |
Ferroelectrics | BaTiO3 | No seed | SiO2 slurry (additive) dropped on BaTiO3 green body; sintering in air (1370 °C, 80 h) | 1.5 cm | k > 200 µm/h | – | [72] |
BZT | BaTiO3 | Pre-sintering of ceramics, then annealing for 100 h with seed on top | (25 × 25 × 5) mm3 | (001)-oriented BZT: k33 = 0.85, d33 ~ 950 pC/N, g33 = 41 × 10−3 Vm/N | Actuators, sensors, transducers | [77] | |
Al-based oxides | Al2O3 | No seed | Sintering in H2 atmosphere (1880 °C) with MgO as sintering aid | up to 30 cm | k ~ 1.5 cm/h; average grain boundary mobility ~ 2 × 10−10 m3/(N s) | – | [80] |
Al2O3 film | c-sapphire | Heat-treating of spin-coated film sample in air (1025 °C, 18 h) | up to 2 µm thickness | k(c-plane) = 5 × 10−2 nm/s; k(r-plane) = 4 × 10−1 nm/s | Patterned single crystal substrates | [86] | |
Nd:YAG | (111) YAG; (110) YAG; (100) YAG | Pre-sintering of ceramics in vacuum (1550 °C, 3 h), then annealing in vacuum | 3‒5 mm | η = 63% (2.4 at. % Nd:YAG) | Solid-state lasers | [42] | |
Other oxides | La9.33Si6O26 | (001) La9.33Si6O26 | Pre-sintering of ceramics in air (1500 °C, 2 h), then annealing with seed on top (1725 °C, 2 h) | – | Conductivity component parallel to the c-axis was ~ 100 times higher than the perpendicular | – | [90] |
LaFeAsO | No seed | Sintering of ceramics with Na-As as sintering aid (1080 °C, 200 h) | (2 × 3 × 0.4) mm3 | Splitting of two transitions at TSDW = 127 K and TS = 145 K; linear behavior of magnetization as a function of magnetic field | High-temperature superconductor | [93] |