Quenchable high-pressure polymorph of zinc selenate.
A new quenchable high-pressure form of zinc selenate (ZnSeO(4)) was produced by subjecting the low-pressure modification to 40 kilobars at 400 degrees C for 30 minutes. The new form is orthorhombic, space group D(2h),(17)-Cmcm. The cell constants at 29 degrees C are: a, 5.511 angstroms; b, 8.110 angstroms; and c, 6.585 angstroms. The calculated density is 4.70 grams per cubic centimeter in comparison with 4.61 grams per cubic centimeter for the low-pressure modification. This implies a volume change of 2 percent at the transition.
Pistorius
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