Who says that you shouldn't put metals in a microwave? Don't try this at home, but high-tech metal compounds can be cooked up inside a humble microwave oven in less time than it takes to warm baked beans. The conditions inside a microwave suit some chemical reactions as they cook foods from the inside out, as those who have messily experimented with eggs will already know. This means that, unlike conventional ovens that can burn the skin of the still-frozen chicken, microwaves distribute heat evenly. And microwaves offer the ideal conditions to combine metals and nitrogen into metal nitrides, Dinesh Agrawal and colleagues at Pennsylvania State University now report. Metal nitrides resist chemical corrosion, wear and high temperatures -- making them extremely useful. Gallium nitride, for example, is a semiconductor that is expected to play a key role in developing high-power, high-temperature electronics like blue-ultraviolet lasers. Other nitrides are used as catalysts (vanadium nitride) and protective coatings (titanium nitride). But nitrides are a pain to make. Temperature control must be precise, the atomised metallic powder can explode and it can take several days for enough nitrogen to diffuse into the metal. Like the chicken, a nitride crust can build up around otherwise untouched aluminium or titanium. Agrawal's team finds that nitrides cook all the way through if they pop the ingredients into a microwave. Admittedly, it is a modified appliance. 'Defrost,' 'full power' and 'simmer' are not accurate enough settings, so the team bypasses the control panel and varies the power externally. Cooling water protects the metal top, and holes drilled through the sides admit a nitrogen supply pipe. Otherwise, it is the same as a microwave from any high-street store and, Agrawal says, entirely safe. Metal powders mixed with solid ammonium chloride are packed into pellets and placed inside the nitrogen supply tube at the oven's centre. Ceramic fibre insulation is packed around the tube before the microwave is turned on. "The insulation is very important," says Agrawal, as temperatures within can reach 1,400°C.