Percolation threshold near the second phase transition in diluted system of Gd2−x(La, Y)xIn |
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Authors: | Ahmad Yazdani |
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Affiliation: | Department of Physics, Tarbiat Modares University, Tehran, Iran |
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Abstract: | In this paper it is demonstrated that the second phase transition of Gd2In intermetallic compound gets eliminated by diluting Gd2−x(LaY)xIn at a critical composition of x=0.5. The exchange coupling for intra-cluster interactions is estimated in the correlation ranges of 3.3 Å<RC<3.6 Å (anisotropic source) and for inter-cluster interactions in the ranges of RC>4 Å where the correlation length is defined as . The sign and strength of the exchange coupling are identified by the eigenvalues λ(k) and are obtained from zeros of the 4×4 matrix of JijRR′ along the three directions of the reciprocal lattice for each dilution (x=0.25, 0.5, 0.75, 1). The transition temperature is calculated using the minimum eigenvalue λmin (k=0, π) which agrees with the experiment. Magnetic field and temperature dependence of the magnetization and electrical resistivity measurements show that: (i) Elimination of the AFM phase is caused by breaking of some FM short-range exchange couplings, and (ii) Conduction electrons order antiferromagnetically at low temperatures and ferromagnetically at high temperatures. |
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Keywords: | 75.30.Kz 75.40.Cx 71.27.+a 71.20.Eh 64.60.&minus i |
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