Tetragonal L1(0) FePt nanoparticles embedded in a robust TiO2 (rutile) matrix (see Figure) are obtained using a modified sol-gel synthesis method followed by metal reduction in a self-generated atmosphere during pyrolysis. The formation of metal nanoparticles is believed to proceed through the clustering of metal atoms inside the rigid and thermoresistant TiO2 network, which both prevents their aggregation and permits them to convert into the desired L1(0) face-centered tetragonal phase.