Synthesis, structural analysis and investigation of photoluminescence properties of mixed metal cation borates

• New synthesis Method: development of mixed metal borates (MMeR(BO 3 ) 2 ; m = Na + , me = Sr 2+ , r = La 3+ , Ce 3+ , Nd 3+ , Sm 3+ , Er 3+ ) using acetates. • Structural Insights : borates feature alkali and alkaline earth metals coordinated by six and nine oxygen atoms, respectively, and rare earth metals coordinated by six oxygen atoms. • Optical Properties: BO 3 groups offer moderate birefringence and broad UV transparency, suitable for nonlinear optical applications. • Characterization: utilized powder X-ray diffraction (P-XRD), fourier transform infrared spectroscopy (FT-IR), inductively coupled plasma (ICP), thermal gravimetric analysis (TGA), and photoluminescence (PL) spectroscopy. • Research Significance: provides new insights into the synthesis and properties of mixed metal borates for potential nonlinear optical applications. The compounds synthesized in this study are mixed metal borates with the structure of MMeR(BO 3 ) 2 ( M =Na + , Me=Sr 2+ , R =La 3+ , Ce 3+ , Nd 3+ , Sm 3+ and Er 3+ ). Solid state method was used for synthesis. Unlike the literature, borates containing three cations were synthesized using acetates of the starting materials. In the structure of borates, alkali and earth metal cations are surrounded by six and nine oxygen atoms, respectively. Rare earth metal cations are surrounded by six oxygen atoms. The complex structure of borates makes them strong candidates for nonlinear optics (NLO) applications. Since boron element (B) is coordinated with three or four oxygen atoms, they not only form planar triangles (BO 3 3− ) or tetrahedral (BO 4 4− ) but also bond with each other to form various structural units. This structural diversity is suitable for the discovery of new compounds with linear optical and nonlinear optical properties. Among these structural units, BO 3 groups have attracted great attention due to their nonlinear optical properties, which are capable of producing moderate birefringence and broad ultraviolet (UV) transparency. Borates that do not contain rare earth metal cations are currently used in nonlinear optical applications to produce high-power visible and ultraviolet light. Due to the importance of borate compounds for industry and research, the aim of the study is to synthesize new types of mixed metal borate compounds and to investigate their structural properties. Powder X-ray diffraction (P-XRD), Fourier transform infrared spectroscopy (FT-IR), Inductively Coupled Plasma (ICP) and Thermal Gravimetric Analysis (TGA) techniques were used for the characterization of the synthesized mixed metal borate structures. Photoluminescence properties were investigated by Photoluminescence (PL) Spectroscopy in the application study.