Colourless, water- and air-stable single crystals of yttrium(III) oxoarsenate(V) Y[AsO₄] in the xenotime-type crystal structure were prepared by the reaction of yttrium sesquioxide (Y₂O₃) dissolved in aqueous nitric acid (13%) with a solution of arsenic(V) oxide hydrate (As₂O₅ ∙ 3 H₂O) and subsequent neutralization with 1 M caustic soda. Y[AsO₄] crystallizes tetragonally in the space group I4₁/amd with the lattice parameters a = 704.63(6) and c = 628.94(5) pm for Z = 4 and is isotypic to the minerals xenotime RE[PO₄] (RE: mainly Y and Yb) and chernovite RE[AsO₄] (RE: mainly Y and Ce). This xenotime-type yttrium compound was used as precursor in a high-pressure experiment (20 kbar) at 700 °C to create a new tetragonal modification of Y[AsO₄]. It shows the scheelite-type structure (space group: I4₁/a) with the lattice parameters a = 498.23(4) and c = 1120.71(9) pm for Z = 4, named after the mineral scheelite (Ca[WO₄]). Both tetragonal structures are characterized by only one crystallographically unique position for each of the Y³⁺, As⁵⁺ and O^2– ions with distances of d(Y–O) = 232 and 241 pm (C.N. = 8) as well as d(As–O) = 169 pm (C.N. = 4) in the case of the scheelite-type structure. The xenotime-type compound shows an unexpected slight decrease in average bond lengths for the yttrium to oxygen (d(Y–O) = 230 and 241 pm, C.N. = 8) as well as for the arsenic to oxygen distances (d(As–O) = 168 pm, C.N. = 4), accompanied by a drastic density increase from D_x = 4.85 (xenotime type) to D_x = 5.44 g ∙ cm^–3 (scheelite type). Luminescence spectroscopic measurements of the Eu³⁺-doped Y[AsO₄] samples, obtained in experiments at similar conditions as for the pure compounds, show a bright, reddish lighting for the scheelite type, which does not occur for the xenotime type of yttrium(III) oxoarsenate(V).

无色，拒水和钇的空气稳定的单晶（III）oxoarsenate（V）Y [ASO ₄ ]在磷钇矿-类型晶体结构通过的三氧化二钇（Y反应制得₂ ö ₃溶解于硝酸水溶液） （13％）用三水合氧化砷（As ₂ O ₅ ∙3 H ₂ O）溶液处理，然后用1 M苛性钠中和。Y [AsO ₄ ]在空间组I 4 ₁ / amd中四方结晶，Z的晶格参数a = 704.63（6）和c = 628.94（5）pm= 4，与矿物质xenotime RE [PO ₄ ]（RE：主要是Y和Yb）和钙长石RE [AsO ₄ ]（RE：主要是Y和Ce）同型。在700°C的高压实验（20 kbar）中，将这种Xenotime型钇化合物用作前体，以产生Y [AsO ₄ ]的新的四边形修饰。它显示了白锌矿型结构（空间群：I 4 ₁ / a），Z = 4时具有晶格参数a = 498.23（4）和c = 1120.71（9）pm，以矿物白钨矿（Ca [WO ₄]）。这两个四方结构的特征是每个Y ³⁺，As ⁵⁺和O ^2–离子只有一个晶体学上唯一的位置，距离d（Y–O）= 232和241 pm（CN = 8）以及d白钨矿型结构时（As–O）= 169 pm（CN = 4）。异种时间型化合物对钇与氧的平均键长（d（Y–O）= 230和241 pm，CN = 8）以及砷与氧的距离（d（As– O）= 168 pm，CN = 4），伴随着密度急剧增加，从D _x = 4.85（xenotime类型）增加到D _x= 5.44 g∙cm ^–3（白钨矿型）。在与纯化合物相似的条件下进行的实验中获得的Eu ³⁺掺杂Y [AsO ₄ ]样品的发光光谱测量结果显示，白钨矿类型的辉光发红光，钇的钇矿类型却不发生这种光。 （III）含氧砷酸盐（V）。