Book excerpt: Selected modern aspects of artificially layered structures and bulk materials involving antiferromagnetic long-range order are the main themes of this book. Special emphasis is laid on the prototypical behavior of Ising-type model systems. They play a crucial role in the field of statistical physics and, in addition, contribute to the basic understanding of the exchange bias phenomenon in MBE-grown magnetic heterosystems. Throughout the book, particular attention is given to the interplay between experimental results and their theoretical description, ranging from the famous Lee-Yang theory of phase transitions to novel mechanisms of exchange bias.