 Cerium magnesium nitrate

Cerium magnesium nitrate is a hydrated double nitrate salt, commonly written $\mathrm{C}{\mathrm{e}}_2\mathrm{M}{\mathrm{g}}_3(\mathrm{N}{\mathrm{O}}_3{)}_{12}\cdot 24{\mathrm{H}}_2\mathrm{O}$. The cerium ions give the crystal a low-temperature magnetic response useful in temperature measurement.^[ref]

In a magnetic thermometer, a measured magnetic susceptibility serves as a temperature-dependent signal. A 1968 comparison found a small offset between powdered and single-crystal thermometers, showing that sample form and calibration matter even for the same salt.^[ref]