Nucleation of an emerging phase has long been one of the major research fields in Science and Engineering. In many cases, interfaces play crucial roles by providing (heterogeneous nucleation) or suppressing (homogeneous nucleation) potential nucleation sites for bulk phase transitions. In this book, an experimental study of phase transitions of long-chain n-alkanes induced by the effect of interfaces is described. In particular, the effect of inert and molecularly smooth solid surfaces and that of gas interfaces are investigated in detail. Given that the vast majority of phase transitions occur via heterogeneous nucleation involving some type of interfaces, this study should shed new and important light in the mechanisms of nucleation and phase transitions. This book, therefore, should be useful to professionals or students in a broad range of fields in Science and Engineering that involve nucleation and phase transitions.