  The dust in protoplanetary disks is influenced by a lot of different
processes. Besides others, heating processes are the most important ones: they
change not only the physical and chemical properties of dust particles, but
also their emission spectra. In order to compare observed infrared spectra of
young stellar systems with laboratory data of hot (up to 700{\deg}C)
circumstellar dust analogues, we investigate materials, which are important
constituents of dust in protoplanetary disks. We calculated the optical
constants by means of a simple Lorentzian oscillator fit and apply them to
simulations of small-particle emission spectra in order to compare our results
with real astronomical spectra of AGB-stars and protoplanetary disks.
