A magnetic material comprises 50-80 wt % of Cobalt, 9-15 wt% of Nickel,
10-25 wt% of Rhenium, 0.1 to 2.0 wt% of Phosphorus, and 5-10 wt % of
Tungsten or Platinum. It can be formed as a layer having good vertical
magnetic properties (e.g. when magnetised it can provide a high magnetic
field strength in the direction perpendicular to the plane of the layer).
The layer preferably has a thickness of above 1 .mu.m. It can be formed
by electroplating. The layer is useful for inclusion in a MEMS device.