Thermal Expansion in Quasi-One-Dimensional, Weakly and Nearly Antiferromagnetic Metals

Thermal expansion in wuasi-one-dimensional (1-D) weakly and nearly antkferromagnetic metals at low temperatures is investigated by using the method of Takahashi and Nakano [3]. The three-dimensional (3-D) character of 1-D weakly and nearly antiferromagnetic metals is phenomenologically considered. this corresponds to taking into account the 3-D character in the 1-D kinetic energy of conduction electrons. The self-consistent renormalization theory of spin fluctuations (the SCR theory) is applied to enable the management of spin fluctuations beyond the random phase approximation. Spin fluctuations are composed of thermal spin fluctuations and zero-point spin fluctuations. We concentrate on thermal spin fluctuations in this study. The effects of thermal spin fluctuations on the thermal expansion are taken into account because the effects of thermal spin fluctuations is much larger than those of zero-point spin fluctuations at low temperatures above the Neel temperature TN. The thermal expansion is studied as the magnetic instability point is approached. We find that the thermal expansion decreases when we introduce a 3-D character into the 1-D electron systems. A strong enhancement of the thermal expansion exists in quasi-1-D weakly and nearly antiferromagnetic metals when the magnetic instability point is approached. KCI Citation Count: 0