[11p-M116-1~15] 1.5 Instrumentation, measurement and Metrology

▲ [11p-M116-12] Determination of thermodynamic properties using ab initio methods for the intermetallic compounds in Nd-Fe-B system

〇(D)Adie Tri Hanindriyo¹, Soumya Sridar², K. C. Hari Kumar², Kenta Hongo^3,4,5, Ryo Maezono³ (1.Grad. Sch. Adv. Sci. Tech., JAIST, 2.Dept. Metal. Mater. Eng.,IITM, 3.Sch. Info. Sci., JAIST, 4.NIMS, 5.PRESTO,JST)

Keywords:DFT+U, neodymium, ab initio

We have investigated the thermodynamic properties of several intermetallic compounds in Fe-Nd, B-Nd and B-Fe-Nd systems using ab initio calculations. DFT+U calculations were performed to predict the enthalpy of formation of NdB₆, NdB₄, Nd₂B₅, Nd₂Fe₁₇ and Nd₅Fe₂B₆ compounds. It was found that the values obtained with an effective Hubbard U correction have better agreement with the experimental data. Vibrational contribution to heat capacity (C_p) as a function of temperature was computed using the quasiharmonic approximation for these compounds. For most of the compounds these properties have not been experimentally determined previously to the best of our knowledge. Our results will serve as useful input for the Gibbs energy model parameter assessment for these systems using the CALPHAD method.