A mosfet can be harder to drive fast than a bi-polar type ! You have the gate CAPACITANCE to charge quickly, and the 8052' limited sourcing drive current may well slow things down a lot, and toast the transistor, since it is turned on relatively slowly.

Look for something cheap like an IRF 530 for a start, but work out for yourself if the 8052 will drive the gate fast enough in this application.

We use a 74HC series buffer to do this on one of our stepper circuits, but there are dedicated drivers that are faster still.

Steve