Spotlight

  • The origin of negative thermal expansion in layered perovskites

    Most materials expand when they are heated, but some do the opposite and shrink, a phenomenon known as negative thermal expansion (NTE). One particular puzzle has been: why is it that ABO3 perovskite materials generally do not exhibit uniaxial negative thermal expansion (NTE) over a wide temperature range, whereas layered perovskite materials of the same chemical family, e.g., A2BO4, often do?