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Superstructure of EU4CD25: a quasicrystal approximant
1Inorganic Chemistry, Arrhenius Laboratory, Stockholm University, 106 91 Stockholm, Sweden. cesar@inorg.su.se
Researchers synthesized the quasicrystal approximant Eu(4)Cd(25), revealing a novel superstructure with the largest cubic unit cell in binary alloys. This material exhibits a reversible phase transition at 782 K.
Area of Science:
- Materials Science
- Solid State Chemistry
- Crystallography
Background:
- Quasicrystal approximants are crystalline materials that mimic the symmetries of quasicrystals.
- Rare-earth metal cadmium compounds (RE-Cd(6)) are known to form complex structures.
- Understanding these structures is key to developing new materials with unique properties.
Purpose of the Study:
- To synthesize and characterize the quasicrystal approximant Eu(4)Cd(25).
- To investigate its crystal structure and identify any novel features.
- To determine its phase transition behavior.
Main Methods:
- Single-crystal X-ray diffraction was used for structural characterization.
- Differential Scanning Calorimetry (DSC) was employed to study phase transitions.
Main Results:
- The synthesis of Eu(4)Cd(25) was successful, with its structure determined.
- Superstructure reflections indicated an F-centered cubic unit cell, the largest reported for binary alloys.
- A reversible phase transition was observed at 782 K.
Conclusions:
- Eu(4)Cd(25) represents a new, complex binary alloy structure.
- The observed superstructure is attributed to ordering of structural features and vacant/occupied Cd(8) cubes.
- The material undergoes a high-temperature reversible phase transition.
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