Al2O3 co-doped with Cr3+ and Mn4+, a dual-emitter probe for multimodal non-contact luminescence thermometry by Mykhaylyk, VB, Kraus, H, Bulyk, L-I, Lutsyuk, I, Hreb, V, Vasylechko, L, Zhydachevskyy, Y, Wagner, A, Suchocki, A