ISSN:
1572-9540
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract A series of hexaborides La1−xEuxB6 (x=0.0–1.0) were synthesized under a pressure of 3.5 GPa and at a temperature of 1600○C using La2O3, Eu2O3 and amorphous boron as the starting materials. The products were characterized by X‐ray Diffraction (XRD) and Mössbauer spectroscopy. XRD data analysis shows that all samples crystallize in a cubic CsCl‐type structure, and the cell volume increases with x. Room temperature 151Eu Mössbauer measurements reveal that Eu ions in all samples are in the divalent state, except for the x=1.0 sample where a small amount of Eu3+ ions was detected. The quadrupole splitting of the Eu2+ ions is positive. Eu ions were reduced from trivalent to divalent during the high‐pressure and ‐temperature processes. The isomer shifts of the Eu2+ ions are all smaller than −12.5 mm/s, suggesting that there is no valence fluctuation in the samples. The hexaborides doped by divalent Eu are not metallic.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1012608304904
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