Acknowledgment First of all I want to express my gratitude to Prof. Dr. Thomas M. Klapötke for the opportunity of this interesting work, the trust he had in me for both my master's and my doctoral thesis, for the scientific freedom he gave me, the opportunity to publish my results in scientific journals and to present them at international conferences, and for his help for dogs in need. The extremely fast answering of e-mails even over several time zones, on weekends or late at night is particularly noteworthy.