K 93 Kurlov, A. S. Magnetic susceptibility and thermal stability of particle size of nanocrystalline tungsten carbide WC [Текст] / A. S. Kurlov, S. Z. Nazarova, A. I. Gusev // Physics of the Solid State. - 2007. - Vol. 49, № 9. - С. 1780-1786. - Библиогр. : с. 1786 (13 назв.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): МАГНИТНАЯ ВОСПРИИМЧИВОСТЬ -- ТЕРМИЧЕСКАЯ УСТОЙЧИВОСТЬ -- КАРБИД ВОЛЬФРАМА -- НАНОКРИСТАЛЛИЧЕСКИЕ КАРБИДЫ Аннотация: The magnetic susceptibility χ of coarse-grained and nanocrystalline tungsten carbides was studied in the temperature range 300–1250 K. The temperature dependence of the susceptibility χ(T) of coarse-grained carbide WC is typical of weak Pauli paramagnets and has no specific features. The χ(T) dependence of nanocrystalline carbide (n-WC) in the range 550–920 K exhibits features associated with annealing of microstrains, which leads to a decrease in the contribution of orbital paramagnetism to the magnetic susceptibility of n-WC and initiates precipitation of minor impurities of iron and cobalt as superparamagnetic particles. A nanocrystalline n-WC powder retains a stable particle size of ~55 nm after long annealing at temperatures of 300 to 1200 K, whereas microstrains relax at 550–920 K Полный текст |