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The novel vanadium oxides Rb 2 CaV 2 O 7 and Cs 2 CaV 2 O 7 have been prepared by solid-state reaction and their crystal structures determined and refined using X-ray, neutron powder and electron diffraction data. Rb 2 CaV 2 O 7 and Cs 2 CaV 2 O 7 are isostructural, crystallizing in space group P 2 1 / n with unit cell parameters: a = 13.8780(1), b = 5.96394(5), c = 10.3376(1) A, β = 104.960(1)° and a = 14.0713(2), b = 6.0934(1), c = 10.5944(1) A, β = 104.608(1)°, respectively. Their crystal structures can be described as a framework of CaO 6 octahedra and V 2 O 7 pyrogroups with alkaline metals found in the tunnels formed. Photoluminescence (PL) and PL excitation spectra of the considered pyrovanadates have been studied in the vacuum ultraviolet (VUV) to visible light (Vis) range as well as their pulse cathode luminescence (PCL) spectra and the kinetic parameters of PCL. In the PL and the PCL spectra of both pyrovanadates recorded at T = 300 K a broad band with maxima at 2.2, 2.4 eV and two shoulders (bands) at 2.0 and 2.58 eV have been observed. At T = 10 K the band at 2.0 eV becomes the main band in the spectra. Two types of luminescence centers for each pyrovanadate, with very similar excitation bands at 3.75, 4.84, 6.2, 7.3 and 9.1 eV, have been found. The nature of the luminescence centers connected with the bands at 2.0, 2.2, 2.4 and 2.58 eV is discussed.

Excitation spectra for intraconfigurational (4f n → 4f n ) and interconfigurational (4f n −1 5d → 4f n ) radiative transitions of trivalent rare earth ions (Sm 3+ , Tb 3+ , Er 3+ , and Tm 3+ ) doped into SrF 2 crystals have been studied using VUV synchrotron radiation and analyzed. The distinctions and peculiarities of excitation mechanisms for 4f n or 4f n −1 5d emitting levels are discussed.