Strongly enhanced thermal expansion in binary Y-Mn intermetallic compounds YMn2, Y6Mn23 and YMn12

Abstract For the three binary compounds YMn 2 , Y 6 Mn 23 and YMn 12 a strong temperature variation of the thermal expansion has been found with values of the coefficient α up to 55 × 10 −6 K −1 . This unusual behaviour of α ( T ) is referred to the existence of two sorts of Mn ionic states whose concentration changes with temperature.