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Updated: Sep 18, 2025
09:06
Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
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Isovalent yet Dissimilar B-Site Occupants in Y2M2O7 Pyrochlore: Repercussions on Structure, Optical Properties, and
Santosh K Sahu1, Rakesh Shukla1,2, Reshmi T Parayil2,3
1Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
Inorganic Chemistry
|June 25, 2025
Summary
Germanium (Ge) substitution in Yttrium Titanate (YTO) ceramics enhances structural stability for nuclear waste immobilization. However, excessive Ge incorporation leads to phase separation, impacting material performance under extreme conditions.
Area of Science:
- Materials Science
- Nuclear Engineering
- Solid State Chemistry
Background:
- Advanced ceramics like pyrochlores (A2B2O7) are crucial for nuclear waste immobilization.
- Understanding B-site ion substitution impacts material properties under extreme conditions.
Purpose of the Study:
- Investigate Germanium (Ge4+) incorporation into Yttrium Titanate (Y2Ti2O7, YTO).
- Analyze the effects of Ge substitution on YTO's structure, electronic environment, and response to extreme conditions.
Main Methods:
- X-ray Diffraction (XRD) for bulk structure analysis.
- Raman Spectroscopy for anionic sublattice investigation.
- X-ray Absorption Spectroscopy (XAS) for local polyhedral changes.
- Europium (Eu3+) photoluminescence (PL) for A-site effects.
Main Results:
- Ge substitution up to 30 mol% was achieved; higher concentrations caused anionic sublattice distortion and phase separation.
- Eu3+ emission confirmed A-site polyhedral distortion with B-site modification.
- Materials showed no phase transitions up to 1200 °C, with decreased thermal expansion coefficients.
- Gamma irradiation caused no lattice damage, but swift heavy-ion irradiation induced greater amorphization in Ge-containing YTO.
Conclusions:
- Ge substitution in YTO offers potential for nuclear waste immobilization but requires careful control to avoid phase separation.
- Modified YTO exhibits good thermal stability and radiation resistance, though heavy-ion resistance is reduced.
- Findings provide insights for designing robust ceramic waste forms.
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