TY - JOUR

T1 - Implementation of Bond’s Scheme in a Single Crystal Diffractometer. Study of the Homogeneity of (Y1–xEux)2O3 Single Crystals

AU - Kudryavtsev, A. L.

AU - Serebrennikova, P. S.

AU - Naumov, N. G.

AU - Gromilov, S. A.

N1 - The work was supported by Russian Science Foundation grant No. 024-22-20017.

PY - 2024/10

Y1 - 2024/10

N2 - Abstract: An original procedure is proposed to refine unit cell parameters (UCPs) of single crystals in Bond’s scheme. The procedure involves the use of a modern laboratory diffractometer equipped with a 2D detector and a three-circle goniometer. At the first stage, preliminary UCPs, diffraction class, and crystal orientation relative to goniometer axes are determined. Then φ and ω angles are calculated to bring an appropriate (occurrence of a well-resolved doublet, intensity) reflection hkl on the equatorial plane. The measurement in Bond’s scheme is carried out at two symmetric positions of the detector ±2θD ≈ 2θhkl. The principal difference from the measurement on a single crystal spectrometer consists in refusing to plot the reflection profile I(ω) and passing to ω-scans with a width of 3-4°, which allows the measurement of the Kα1/Kα2 doublet profile. After its processing by two independent 2D functions, coordinates of the maxima are determined, and then the 4θhkl. Angle is found based on angular sizes of the detector pixel and the difference in the coordinates of X Kα1-component reflections obtained in symmetric positions. In this approach, measurement errors are related to the accuracy of placing the detector in two symmetric positions and the correctness of processing 2D reflection profiles. In the study of reference Si and Ge single crystals in the range of 2θD angles close to 100°, UCP deviations from the theoretical values are found to not exceed 0.0004 Å, and the relative measurement accuracy is 6·10–5. The refinement of UCPs of single crystals grown in the Y2O3–Eu2O3 system by the melt-solution technique indicates the formation of the (Y1–xEux)2O3 solid solution with the x value range of 0.27-0.40. A scheme is proposed to improve the measurement accuracy when the procedure is transferred to the diffractometer with synchrotron radiation.

AB - Abstract: An original procedure is proposed to refine unit cell parameters (UCPs) of single crystals in Bond’s scheme. The procedure involves the use of a modern laboratory diffractometer equipped with a 2D detector and a three-circle goniometer. At the first stage, preliminary UCPs, diffraction class, and crystal orientation relative to goniometer axes are determined. Then φ and ω angles are calculated to bring an appropriate (occurrence of a well-resolved doublet, intensity) reflection hkl on the equatorial plane. The measurement in Bond’s scheme is carried out at two symmetric positions of the detector ±2θD ≈ 2θhkl. The principal difference from the measurement on a single crystal spectrometer consists in refusing to plot the reflection profile I(ω) and passing to ω-scans with a width of 3-4°, which allows the measurement of the Kα1/Kα2 doublet profile. After its processing by two independent 2D functions, coordinates of the maxima are determined, and then the 4θhkl. Angle is found based on angular sizes of the detector pixel and the difference in the coordinates of X Kα1-component reflections obtained in symmetric positions. In this approach, measurement errors are related to the accuracy of placing the detector in two symmetric positions and the correctness of processing 2D reflection profiles. In the study of reference Si and Ge single crystals in the range of 2θD angles close to 100°, UCP deviations from the theoretical values are found to not exceed 0.0004 Å, and the relative measurement accuracy is 6·10–5. The refinement of UCPs of single crystals grown in the Y2O3–Eu2O3 system by the melt-solution technique indicates the formation of the (Y1–xEux)2O3 solid solution with the x value range of 0.27-0.40. A scheme is proposed to improve the measurement accuracy when the procedure is transferred to the diffractometer with synchrotron radiation.

KW - accuracy

KW - reference sample

KW - single crystal X-ray diffraction

KW - unit cell parameters

KW - yttrium oxide

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85209781993&origin=inward&txGid=e103acadb1be8f3606532d1e621de900

UR - https://www.mendeley.com/catalogue/59ce7248-24a0-3048-9386-aa6fc561633e/

U2 - 10.1134/S0022476624100056

DO - 10.1134/S0022476624100056

M3 - Article

VL - 65

SP - 1932

EP - 1941

JO - Journal of Structural Chemistry

JF - Journal of Structural Chemistry

SN - 0022-4766

IS - 10

ER -