No, you are not permitted to mix studded and non-studded winter tyres on your car.
When you are required to use winter tyres you may use either studded or non-studded (so called friction tyres) winter tyres, but you must not mix – all tyres must be either studded or non-studded.
Studded tyres provide better grip and shorter braking distances on icy surfaces, but can result in longer braking distances on snow-free surfaces. On snow, studded tyres and non-studded winter tyres are about equally effective.