The compressional behaviour of a natural allanite from Lago della Vecchia (upper Cervo valley, Italy) metagranitoids [A1($$ {\text{Ca}}_{0.69}{\text{Fe}}_{0. 3 1}^{ 2+ } $$Ca0.69Fe0.312+)Σ1.00A2(Ca0.46Ce0.24La0.12Sm0.02Pr0.05Nd0.09Th0.02)Σ1.00M1($$ {\text{Al}}_{0.65}{\text{Fe}}_{0. 3 4}^{ 3+ } $$Al0.65Fe0.343+Ti0.02)Σ1.01M2(Al0.99)M3($$ {\text{Fe}}_{0. 5 4}^{3 + } {\text{Fe}}_{0. 3 6}^{ 2+ } $$Fe0.543+Fe0.362+Mg0.06$$ {\text{Ti}}_{0.0 2}^{ 4+ } $$Ti0.024+Al0.01)Σ0.99Si1,Si2,Si3(Si2.80Al0.20)Σ3.00O11(OH,O)] has been investigated up to 16 GPa (at 298 K) by means of in situ synchrotron single-crystal X-ray diffraction. Experiments have been conducted under hydrostatic conditions, using a diamond anvil cell and the mix methanol:ethanol:water = 16:3:1 (up to 10 GPa) and neon (up to 16 GPa) as pressure-transmitting media. No phase transition has been observed within the pressure-range investigated. Data collected in decompression prove that, at least up to 16 GPa (at 298 K), the deformation mechanisms are fully reversible. A third-order Birch–Murnaghan Equation of State (BM-EoS) was fitted to the P–V data (up to 10 GPa), giving: V0 = 470.2(2) Å3, KP0,T0 = 131(4) GPa and K′= 1.9(8). The evolution of the lattice parameters with pressure shows a slight anisotropic compression pattern, with KP0,T0(a):KP0,T0(b):KP0,T0(c) = 1.24:1.52:1. The monoclinic β-angle decreases monotonically with pressure, with: βP(°) = βP0 – 0.0902(4)P (R2 = 0.997, with P in GPa). The main deformation mechanisms at the atomic scale are described based on a series of structure refinements at different pressures. A comparison between the compressional behavior of allanite, epidote and clinozoisite is carried out.

中文翻译：

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高压下的铝榴石：稀土元素对绿帘石族矿物弹性行为的影响

来自 Lago della Vecchia（上 Cervo 山谷，意大利）变花岗岩 [A1($$ {\text{Ca}}}_{0.69}{\text{Fe}}_{0. 3 1}^ { 2+ } $$Ca0.69Fe0.312+)Σ1.00A2(Ca0.46Ce0.24La0.12Sm0.02Pr0.05Nd0.09Th0.02)Σ1.00M1($$ {\text{Al}}_{0.65} {\text{Fe}}_{0. 3 4}^{ 3+ } $$Al0.65Fe0.343+Ti0.02)Σ1.01M2(Al0.99)M3($$ {\text{Fe}} _{0. 5 4}^{3 + } {\text{Fe}}_{0. 3 6}^{ 2+ } $$Fe0.543+Fe0.362+Mg0.06$$ {\text{ Ti}}_{0.0 2}^{ 4+ } $$Ti0.024+Al0.01)Σ0.99Si1,Si2,Si3(Si2.80Al0.20)Σ3.00O11(OH,O)]已被研究通过原位同步加速器单晶 X 射线衍射达到 16 GPa（在 298 K）。实验是在静水压条件下进行的，使用金刚石砧座和混合甲醇:乙醇:水 = 16:3:1（高达 10 GPa）和氖（高达 16 GPa）作为压力传输介质。在所研究的压力范围内没有观察到相变。减压收集的数据证明，至少高达 16 GPa（298 K），变形机制是完全可逆的。三阶 Birch-Murnaghan 状态方程 (BM-EoS) 被拟合到 P-V 数据（高达 10 GPa），给出：V0 = 470.2(2) Å3, KP0,T0 = 131(4) GPa 和K'= 1.9(8)。晶格参数随压力的演变显示出轻微的各向异性压缩模式，KP0,T0(a):KP0,T0(b):KP0,T0(c) = 1.24:1.52:1。单斜 β 角随压力单调减小，其中：βP(°) = βP0 – 0.0902(4)P（R2 = 0.997，P 为 GPa）。基于在不同压力下的一系列结构改进来描述原子尺度的主要变形机制。对膨润土的压缩行为的比较，