Structural perfection of Fe1-Ga BO3 single crystals designed for nuclear resonant synchrotron experiments

• A series of Fe 1- x Ga x BO 3 (0 ≤ x ≤ 1) single crystals was grown by the upgraded flux technique. • Crystal perfection was analyzed using HR TEM, electron diffraction, XRD and X-ray topography. • A series of topographic images creates a " angular movie" that visualizes the local crystalline structure. • It was found that each of the studied Fe 1- x Ga x BO 3 crystals (0 ≤ x ≤ 1) contains defect-free regions. • It is concluded that Fe 1- x Ga x BO 3 can be used as monochromators for synchrotron experiments based on nuclear resonances. A series of Fe 1- x Ga x BO 3 single crystals was grown by the flux technique. The atomic structure of crystals has been investigated by high-resolution electron microscopy. Crystal structure perfection of the crystals with 0 ≤ x ≤ 1 was studied by X-ray diffraction and X-ray topography, and structural defects were visualized. Comparison of the experimental and calculated data for crystals of the extreme members of the series FeBO 3 and GaBO 3 with the crystals of solid solutions Fe 1- x Ga x BO 3 revealed a slight decrease in the structural perfection of “mixed” crystals where partial isomorphic substitution of iron for gallium occurs. Along with this, each of the studied samples contains regions free of defects and stresses. The results of this work have demonstrated the possibility of using Fe 1- x Ga x BO 3 crystals as monochromators in synchrotron experiments based on nuclear resonances.