Lattice definability of certain matrix rings

Let R = M-n(K) be the ring of square matrices of order n >= 2 over the ring K = Z/p(k)Z, where p is a prime number, k is an element of N. Let R' be an arbitrary associative ring. It is proved that the subring lattices of the rings R and R' are isomorphic if and only if the rings R and R' are themselves isomorphic. In other words, the lattice definability of the matrix ring M-n(K) in the class of all associative rings is proved. The lattice definability of a ring decomposable into a direct (ring) sum of matrix rings is also proved. The results obtained are important for the study of lattice isomorphisms of finite rings.