Thermal properties ofCaMoO4: Lattice dynamics and synchrotron powder diffraction studies

Abstract

The structure of calcium molybdate was studied by means of synchrotron based high-resolution powder diffraction methods in the temperature range 12-300 K. The scheelite structure type was confirmed for CaMoO 4 in the temperature region investigated and no structural anomalies were observed. Thermal expansion coefficients extracted from the thermal dependencies of the cell sizes are found to be in good agreement with the predictions from our lattice dynamics calculations that form the background for microscopic interpretation of the experimental data. From the analyses of experimental results and the calculated thermal expansion coefficients, elastic constants, phonon density of states, heat capacities, entropy, and Grüneisen parameters it is concluded that a quasiharmonic lattice dynamics approach provides a good description of these properties for CaMoO 4 at temperatures below 800 K.

Growth and characterization of isotopically enriched 40Ca100MoO4 single crystals for rare event search experiments

“…Each layer has a two-dimensional CsCl arrangement of a Ca cation and an anion complex (MoO 4 ) surrounded by eight ions of opposite sign (see fig. 1 in [16]). There are at least two optimal directions for seeding and further growth of the CaMoO 4 crystal.…”

Different Origins of Green-Light Photoluminescence Emission in Structurally Ordered and Disordered Powders of Calcium Molybdate

“…[7][8][9][10] More recently, CM is being studied as a material for cryogenic phonon scintillation detector applications. 11 By using time-resolved spectroscopy, Leonelli and Brebner proposed a model to describe the luminescence process whereby electrons form small polarons that interact with holes to produce self-trapped excitons (STEs), with the recombination of STEs resulting in the visible emission, either immediately or after being trapped for a certain time by impurities and defects. 12,13 As a result of previous studies of photoluminescence (PL) properties, we recently reported that two mechanisms were found to be responsible for PL emission in CaWO 4 and CM powders.…”

Влияние решеточного и спин-фононного вкладов на температурное поведение расщепления основного состояния Gd-=SUP=-3+-=/SUP=- в SrMoO-=SUB=-4-=/SUB=-

“…Чтобы проверить достоверность применения (2), мы провели аналогичную процедуру с данными работы [19] для CaMoO 4 , взятыми в диапазоне T ∼ 300−1273 K. Полученные нами a(T ) и c(T ) неплохо совпадают с экспериментальными результатами [20] в области T = 10−300 K. Используя (2) с определенными выше a i и c i , мы расcчитали параметры решетки SrMoO 4 при нужных T , а затем и сферические координаты R, θ, ϕ ближайших к Gd 3+ 8 ионов кислорода (O 2− ) в чистой решетке SrMoO 4 . Координаты x, y, z этих O 2− взяты из данных работы [21].…”