The articles of this book, dated between 2011 and 2020, represent the final results of an investigation of solid-state phase transitions undertaken by Yuri Mnyukh in 1959. The initial purpose of the study was to reveal how a crystal structure changes into a different structure. A number of key experimental discoveries by Mnyukh and his graduate students had shown that the process is always a crystal growth. From these experiments the nucleation-and-growth...