1 23 Journal of Thermal Analysis and Calorimetry An International Forum for Thermal Studies ISSN 1388-6150 Volume 117 Number 2 J Therm Anal Calorim (2014) 117:573-578 DOI 10.1007/s10973-014-3791-6 Novel red-emitting phosphors, (Mg (1−x −y) Mn x Dy y )Al 2 Si 2 O 8 and (Mg (1−x −y) Mn x Tm y )Al 2 Si 2 O 8 Esra Öztürk, Nilgun Kalaycioglu Ozpozan & Serkan Dayan