If these smoke detectors are residential stand-alone smoke alarms, that is they have sounders in them, and if these are going to talk to each other so if one goes into alarm, all of them sound off, then they all have to be of the same manufacturer and they have to be compatible with each other. The manufacturer will say on the box whether they are compatible and can be used together.
Ion, Photo, and Combination Detector Alarms all can be considered to be just smoke alarms and are useable with each other. If the other compatibility issues are taken care of, there should be no problem with using them together as long as the instructions that come with the detectors are followed.
Douglas Krantz