ar X iv : m tr l - th / 9 41 10 04 v 1 1 6 N ov 1 99 4 Three - dimensional electronic instabilities in polymerized solid A
نویسندگان
چکیده
The low-temperature structure of AC 60 (A=K, Rb) is an ordered array of polymerized C 60 chains, with magnetic properties that suggest a non-metallic ground state. We study the paramagnetic state of this phase using first-principles electronic-structure methods, and examine the magnetic fluctuations around this state using a model Hamiltonian. The electronic and magnetic properties of even this polymerized phase remain strongly three dimensional , and the magnetic fluctuations favor an unusual three-dimensional anti-ferromagnetically ordered structure with a semi-metallic electronic spectrum.
منابع مشابه
ar X iv : m tr l - th / 9 41 20 02 v 1 2 D ec 1 99 4 Commensurate and modulated magnetic phases in orthorhombic A
Competing magnetically ordered structures in polymerized orthorhombic AC 60 are studied. A mean-field theory for the equilibrium phases is developed using an Ising model and a classical Heisenberg model to describe the competition between inter-and intra-chain magnetic order in the solid. In the Ising model, the limiting commensurate one-dimensional and three-dimensional phases are separated by...
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