“…During melting, the density of tin changes dramatically from 7176.1 kg m −3 to 6982.2 kg m −3 , 46 which corresponds to a sharp change in volume of 2.8%. In this case, it is assumed that part of the tin particles break the carbon shell, the thermal expansion of which is significantly less, 47,48 and escape from it, leaving empty shells behind. Such structures begin to appear in the material heated to a temperature of 265 °C ( Fig.…”