Synthesis, densification, microstructure, and mechanical properties of samarium hexaboride ceramic

Abstract

Samarium hexaboride (SmB6) powders were synthesized by boro/carbothermal reduction of Sm2O3 with B4C. Nominally pure SmB6 powder had a mean particle size of about 400 nm and an oxygen content of 0.12 wt%. SmBO3 formed as an intermediate phase during the synthesis. The synthesized powder was hot pressed at 1950°C to produce SmB6 ceramics with relative densities >99.6% and a mean grain size of 4.4 μm. Vickers’ hardness was 20.1 ± 0.7 GPa. Young's modulus measured by bending and ultrasonic methods was 271 and 244 GPa, respectively. The flexure strength was 253 ± 79 MPa and fracture toughness was 2.1 ± 0.1 MPa m1/2. These are the first reported results of the microstructure and bulk mechanical behavior of SmB6 ceramics.

Metal Borides: From Industrial Classics to Versatile Colloidal Nanocrystals for Energy, Catalysis, and Hard Coatings Applications

“…The high-temperature methods (1000–1600 °C) such as solid-state reactions, , melt electrolysis and flux technique, − vapor depositions and metal gas reactions to produce nanostructured hexaborides, − combustion synthesis, the densification process, hot pressing, , spark plasma sintering, pressureless sintering, and sol–gel synthesis − are used to synthesize bulk metal borides. However, very few of those techniques could actually be adopted to nanoscale metal borides.…”

Особенности структуры поверхности и поверхностного электронного транспорта в коррелированном топологическом изоляторе SmB-=SUP=-VI-=/SUP=-

“…В настоящее время для подготовки поверхности SmB 6 в основном применяются механическая и (или) химическая полировка (травление). При обработке поверхности механической полировкой используются суспензии на основе алмазных порошков, Al 2 O 3 или SiC [5,6]. Однако в процессе обработки поверхности такими суспензиями вносятся существенные нарушения структурного совершенства в приповерхностном слое, толщина которого может составлять от десятков нанометров до нескольких микрон [7].…”