The calculating results showed that the melting temperature of alloys increases with increasing pressure. The melting temperatures of defect alloys of AgCe, Ag2Ce and Ag3Ce are always slightly lower than that of perfect alloys. Especially, the melting temperatures value of the perfect and defect alloys were almost the same at high pressure. The melting temperature of alloys increase with an increase in amount of Ag containing in the alloys. | Communications in Physics, Vol. 28, No. 2 (2018), pp. 155-162 DOI: STUDYING THE EFFECTS OF VACANCIES ON THE MELTING TEMPERATURE OF AGCE ALLOY DANG THANH HAIa,† , VU VAN HUNGb AND GIANG THI HONGc a Vietnam Education Publishing House b University of Education, Vietnam National Uiversity Hanoi c Faculty of Physics, Hanoi National University of Education † E-mail: dthai@ Received 21 February 2018 Accepted for publication 7 May 2018 Published 16 June 2018 Abstract. In order to evaluate the effects of vacancies on the melting temperature of AgCe alloy, the statistical moment method was used to find out the analytical expressions to determine the Gibbs free energy in the AB substitution alloy and the expression to calculate the melting temperature of perfect and defect AB substitution alloys. The melting temperature was calculated by the numerical calculation method on the perfect and defect AgCe alloys. The calculating results showed that the melting temperature of alloys increases with increasing pressure. The melting temperatures of defect alloys of AgCe, Ag2 Ce and Ag3 Ce are always slightly lower than that of perfect alloys. Especially, the melting temperatures value of the perfect and defect alloys were almost the same at high pressure. The melting temperature of alloys increase with an increase in amount of Ag containing in the alloys. The calculated results agreed well with the experimental results at zero pressure. Keywords: statistical moment method, rare earth, rare earth alloys, melting temperature, vacancy. Classification numbers: , , , . c 2018 Vietnam Academy of Science and Technology 156 DANG THANH HAI, VU VAN HUNG AND GIANG THI HONG I. INTRODUCTION Metals and rare earth alloys are a strategic material for high-tech industries such as electronics, nuclear, optics, superconducting materials, super-magnets, metallurgy. Some materials made from rare earth oxides in nanoscale are
