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Amorphous Ferro- and Antiferromagnetism Within an RPA-CPA Theory

  • Raza A. Tahir-Kheli

Abstract

We consider the system to be governed by a Heisenberg spin Hamiltonian with vanishing external field, i.e. u→0
$$H = A\sum\limits_{f,p} {J(f,p)} {S_f}.{S_p} - \mu \sum\limits_I {S_f^z} $$
(1)
Here A=−1 for the ferromagnetic case and +l for the antiferromagnetic case. The exchange integral between any site p and its surrounding shell of atoms (which we take to consist of z atoms on the average) is to be random with a probability distribution P(J) such that P(J) is zero outside the range J2>J >J1 and
$$\int\limits_{{J_1}}^{{J_2}} P \left( J \right)dJ = 1. $$
(2)
( Note that it is the fluctuations in the neighboring environment, in general, and in the separation vectors (f-p) as compared with the corresponding vectors for a crystalline lattice of coordination z , in particular, which cause these fluctuations in the exchange integral J(f,p).

Keywords

Spin Wave Coherent Potential Approximation Heisenberg Spin Amorphous System Magnetic Long Range Order 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Plenum Press 1973

Authors and Affiliations

  • Raza A. Tahir-Kheli
    • 1
  1. 1.Department of PhysicsTemple UniversityPhiladelphiaUSA

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