Both lead telluride and tin telluride are polar semiconductors [187]
and crystallize in the rock-salt (NaCl) structure [188]. The melting
temperatures for PbTe and SnTe are
and
,
respectively [189]. At high pressures, PbTe recrystallizes in an
orthorhombic structure [190], as transists SnTe to at temperatures
lower than
[191].