Preparation of the crack-free single phase (Zn1-xCdx)13Sb10 by a gradient freeze method and their structural and thermoelectric properties

► The effect of Cd substitution on the thermoelectric property of Zn13Sn10 is reported. ► The crack-free single phase was successfully obtained by a gradient freeze method. ► The solubility limit of Cd was determined. ► The ZT is enhanced by 10% by the substitution.