GRIFFITHS SINGULARITY IN A NON-DILUTE ISING CHAIN

It is known that a one-dimensional random Ising model with a magnetic field h and two types of exchange bonds, K2= infinity and K1=0, has a Griffiths singularity in its magnetisation. Two arguments, one based on expansion in the concentration of K2 bonds and the other on decimation, are given which imply that a Griffiths singularity persists when K1 not=0. The possibility of Griffiths singularities in non-dilute random magnets of higher dimension is briefly discussed.