Good crystalline quality CaF2 sub-micron size particles doped with neodymium ions have been produced by the co-precipitation process and their crystallinity have been further improved by thermal treatment at 500 degrees C. Core and surface related luminescence defect centres have been identified and the effects of Y3+ and Yb3+ codopants are also investigated. Core defects centres are associated with single-ion and multiion defect centres as observed in bulk single crystal whereas the origin of the surface or near surface defect, A', centre has been ascertained to be derived from a single-ion centre most probably charge compensated by a hydroxyl group. (C) 2017 Elsevier B.V. All rights reserved.