they lose at least 20 of their conversion efficiency in comparison with the efficiency at room temperature until now the led temperature was kept at temperatures which are as low as possible by means of complex cooling measures which in many cases are not tolerated by the market and in many applications are not possible for reasons of space the new mixed sion in this case offers a superior solution however it can also be used for other light sources for example conventional lamps such as high pressure discharge lamps and fluorescent lamps the new mixed phase can also be mixed with other phases of sions in particular sr sion particularly surprising is the fact that the new phase can be even more efficient than garnet phosphors and can therefore even replace yag ce in order to obtain the new phase as purely as possible a suitable production process needs to be used in this case the synthesis from nitrides as has usually been applied up until now is less recommended since nitrides cannot be produced with a particularly fine particle size in order to achieve intimate mixing of the sr and ba precursors however it is favorable to use sr and ba precursors which have as fine a particle size as possible and which have a maximum d50 measured using a sedigraph of at most 5 u03bcm preferably even at most 3 u03bcm favorable results are achieved with precursors which have a d50 of between 1.