The growth characteristics and the magnetic properties of Mn‐substituted garnet films grown on (110) oriented substrates are reported. On perfectly oriented substrates hillocks are observed which occur due to the fact that (110) is a habit face. By the introduction of a slight misorientation of the substrates, the hillocks disappear and the surfaces are perfectly flat. Mn is substituted in the garnet to obtain the right magneto‐elastic properties. It is shown that the temperature dependence of the magnetic parameters can be adjusted such as required to provide a device material.