Magnetic materials with negative thermal expansion

Magnetic compounds with remarkably anomalistic thermal expansion which were discovered domestically and overseas in recent years are reviewed. These include Mn3AX of anti-perovskite structure, R2Fe17-xMxCy of Th2Zn17 structure, and R1-xAxMnO3 of perovskite structure. The mechanism of negative thermal expansion is qualitatively analyzed, and further investigations are proposed with a view to practical applications.