While the pressure-temperature diagrams (PT diagrams) are useful for discerning the phase of a substance at certain operating conditions, other types of phase diagrams exist. For example, there are phase diagrams which describe the phase of a mixture of two compounds verses temperature. [[Metal]]lurgists also use a special type of phase diagram to describe solid-solid alloys, which have different "phases," or different ways the molecules [[crystal]]ize depending on the composition of the [[alloy]] at the temperature at which it is held.<ref name="Callister">Callister Jr., William D. ''Materials Science and Engineering: An Introduction, 6e". Von Hoffman Press: 2003.</ref> | While the pressure-temperature diagrams (PT diagrams) are useful for discerning the phase of a substance at certain operating conditions, other types of phase diagrams exist. For example, there are phase diagrams which describe the phase of a mixture of two compounds verses temperature. [[Metal]]lurgists also use a special type of phase diagram to describe solid-solid alloys, which have different "phases," or different ways the molecules [[crystal]]ize depending on the composition of the [[alloy]] at the temperature at which it is held.<ref name="Callister">Callister Jr., William D. ''Materials Science and Engineering: An Introduction, 6e". Von Hoffman Press: 2003.</ref> |