Synthetic process and spark plasma sintering of SrIrO3 composite oxide

Abstract

Single phase of SrIrO 3 powders and ceramics were obtained by solid-state chemical reaction method and spark plasma sintering (SPS) technique, respectively. Phase evolutions, characteristics, morphology and resistivity of the samples were studied by using thermogravimetric analysis-differential scanning calorimetry (TG-DSC), X-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM) and four-point probe method, respectively. The results showed that the reaction process to form SrIrO 3 phase occurred between SrCO 3 and IrO 2 directly during the heating process. By using optimum fabrication conditions established from the TG-DSC results, single phase of SrIrO 3 powders was synthesized at 800-1000 ℃. SrIrO 3 ceramics were sintered by SPS technique at 1000-1100 ℃ with a pressure of 30 MPa, showing a high relative density of 92%-96% and dense microstructure. The room-temperature resistivity of SrIrO 3 ceramics was about 2×104 Ωm. The present study can provide high-quality ceramic target for the preparation of SrIrO 3 films in traditional physical vapor deposition (PVD) method.

Metal–Insulator Transition of LaNiO3 Films in LaNiO3/SrIrO3 Heterostructures

“…Prior to the deposition, the STO substrates were treated with buffered hydrofluoric acid followed by annealing in flowing O 2 at 950 °C for 75 min to achieve a TiO 2 -terminated surface. LNO and SIO targets were prepared via a conventional solid-state reaction from analytical reagents La 2 O 3 and NiO, and SrCO 3 and IrO 2 , respectively. , An appropriate amount of La 2 O 3 and NiO was thoroughly mixed and then calcinated at 900 °C for 12 h. The obtained powders were grounded, pressed as pellets, and sintered at 1200 °C for 24 h to obtain the LNO target. SIO target was achieved in a similar process, with the calcination performed at 850 °C for 9 h and the sintering performed at 950 °C for 9 h. Deposition parameters used are the same for both LNO and SIO layers.…”

Epitaxial growth and thermodynamic stability of SrIrO3/SrTiO3 heterostructures

“…At atmospheric pressure, SrIrO 3 crystallises in a 6H-hexagonal structure, while its perovskite form can be obtained by applying high pressure and temperature and subsequent quenching 9 . This requires particular care due to the high volatility of iridium oxides and competition with other phases such as Sr 2 IrO 4 and Sr 3 Ir 2 O 7 10 . These extreme conditions can be avoided by resorting to thin film growth, where epitaxial constraint can be used to synthesize perovskite SrIrO 3 films 8,[11][12][13][14][15][16][17][18][19] .…”