Browsing by Author "Lagos, Miguel"
Now showing items 1-7 of 7
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Gottlieb, David; Lagos, Miguel; Hallberg, Karen; Balseiro, Carlos (1991)We introduce an approximate analytic solution for the S=1/2 one-dimensional antiferromagnetic Heisenberg model with coupling between nearest- and next-nearest-neighbor spins. Closed-form expressions for the ground state, ...
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Lagos, Miguel; Rogan Castillo, José; Schuller, Ivan K. (1991)We reanalyze a recent paper by Kim et al. [Phys. Rev. B 38, 5716 (1988)] regarding the kinetics of hydrogen uptake by niobium surfaces. We show that the kinetic analysis performed by these authors is incorrect. © 1991 The ...
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Lagos, Miguel (American Inst of Physics, 2000)The dependence of the superplastic flow on the efficiency of grain boundaries for capturing and releasing vacancies is demonstrated. It is emphasized that this flow is dependent mostly on the sensitivity of this ability ...
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Lagos, Miguel; Gottlieb, David (1993)We examine the nature of the singlet excitations introduced recently to describe the spin dynamics of the antiferromagnetic Heisenberg model with anisotropic coupling. It is shown that they excite spin waves polarized ...
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Gottlieb, David; Montenegro, Maximiliano; Lagos, Miguel; Hallberg, Karen (1992)We present a variational approach to the Heisenberg antiferromagnetic model for spin 1/2 and anisotropic exchange, with an external longitudinal and transverse magnetic field. In the one-dimensional case, we calculate ...
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Lagos, Miguel (2006)The plastic flow of a polycrystal is calculated assuming that no sliding does occur if the in-plane components of the shear stress acting on the common grain boundary of two grains are below a threshold stress τc. Otherwise ...
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Lagos, Miguel (2005)A fine mechanical analysis of a polycrystalline material subjected to large stresses must distinguish between intergranular and crystalline matter because they have different mechanical properties. Homogeneity is an illusion ...