Measurements of the differential elastoresistance of URu$_2$Si$_2$ reveal that the fluctuations associated with the 17 K Hidden Order phase transition have a nematic component. Approaching the Hidden Order phase transition from above, the nematic sus
ceptibility abruptly changes sign, indicating that while the Hidden Order phase has a nematic component, it breaks additional symmetries.
We present a tutorial on the principles of crystal growth of intermetallic and oxide compounds from molten solutions, with an emphasis on the fundamental principles governing the underlying phase equilibria and phase diagrams of multicomponent systems.
