J. PrasongkitI. M. TangMahidol University2018-07-242018-07-242004-12-01Journal of Magnetism and Magnetic Materials. Vol.284, No.1-3 (2004), 376-382030488532-s2.0-10044277259https://repository.li.mahidol.ac.th/handle/20.500.14594/21816The two sub-lattice model is modified to take into account the presence of two types of transition metal ions in GdCo4-xNixAl. An expression for magnetization is obtained and is used to fit the experimental results of Burzo and Pop (J. Magn. Magn. Mater. 196-97 (1999) 768)). From the values of the molecular field coefficients nij(i,j=Gd, Co or Ni), the values of the exchange interactions JGdGd,JGdCo,JGdNi,JCoCo,JCoNi,and JNiNi,were found. It is seen that three of them, JGdGd,JNiNi,and JGdNi,exhibit clear exponential decreases as the Ni content increases; one of them, JCoCo,exhibits a clear exponential increase. The other two exchange interactions, JGdCoappear to exhibit a parabolic (inverted parabolic) dependence on the Ni content. © 2004 Elsevier B.V. All rights reserved.Mahidol UniversityPhysics and AstronomyArticleSCOPUS10.1016/j.jmmm.2004.07.003