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Temperature-dependent synchrotron X-ray diffraction, pair distribution function and susceptibility study on the layered compound CrTe3

DOI: 10.1515/zkri-2017-2100 DOI Help

Authors: Anna-Lena Hansen (Universität Kiel) , Bastian Dietl (Universität Kiel) , Martin Etter (Deutsches Elektronen-Synchrotron (DESY)) , Reinhard K. Kremer (Max-Planck-Institut für Festkörperforschung) , David C. Johnson (University of Oregon) , Wolfgang Bensch (Universität Kiel)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Zeitschrift Für Kristallographie - Crystalline Materials

State: Published (Approved)
Published: December 2017

Abstract: Results of combined synchrotron X-ray diffraction and pair distribution function experiments performed on the layered compound CrTe3 provide evidence for a short range structural distortion of one of the two crystallographically independent CrTe6 octahedra. The distortion is caused by higher mobility of one crystallographically distinct Te ion, leading to an unusual large Debye Waller factor. In situ high temperature X-ray diffraction investigations show an initial crystallization of a minor amount of elemental Te followed by decomposition of CrTe3 into Cr5Te8 and Te. Additional experiments provide evidence that the Te impurity (<1%) cannot be avoided. Analyses of structural changes in the temperature range 100–754 K show a pronounced anisotropic expansion of the lattice parameters. The differing behavior of the crystal axes is explained on the basis of structural distortions of the Cr4Te16 structural building units. An abrupt distortion of the structure occurs at T≈250 K, which then remains nearly constant down to 100 K. The structural distortion affects the spin exchange interactions between Cr3+ cations. A significant splitting between field-cooled (fc) and zero-field-cooled (zfc) magnetic susceptibility is observed below about 200 K. Applying a small external magnetic field results in a substantial spontaneous magnetization, reminiscent of ferro- or ferrimagnet exchange interactions below ~240 K. A Debye temperature of ~150 K was extracted from heat capacity measurements.

Journal Keywords: CrTe3; in situ diffraction methods; layered material; pair distribution function

Subject Areas: Materials, Chemistry

Instruments: I15-Extreme Conditions

Other Facilities: DESY

Added On: 05/01/2018 09:59

Discipline Tags:

Inorganic Chemistry Materials Science Chemistry

Technical Tags:

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