Failamani, Fainan;
Malik, Zahida;
Salamakha, Leonid;
Kneidinger, Friedrich;
Grytsiv, Andriy;
Michor, Herwig;
Bauer, Ernst;
... Rogl, Peter; + view all
(2016)
BaAl₄ derivative phases in the sections {La,Ce}-Ni₂Si₂-{La,Ce}Zn₂Si₂: phase relations, crystal structures and physical properties.
Dalton Transactions
, 45
pp. 5262-5273.
10.1039/c5dt04705f.
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Abstract
Phase relations and crystal structures have been evaluated within the sections LaNi2Si2–LaZn2Si2 and CeNi2Si2–CeZn2Si2 at 800 °C using electron microprobe analysis and X-ray powder and single crystal structure analyses. Although the systems La–Zn–Si and Ce–Zn–Si at 800 °C do not reveal compounds such as “LaZn2Si2” or “CeZn2Si2”, solid solutions {La,Ce}(Ni1−xZnx)2Si2 exist with the Ni/Zn substitution starting from {La,Ce}Ni2Si2 (ThCr2Si2-type; I4/mmm) up to x = 0.18 for Ce(Ni1−xZnx)2Si2 and x = 0.125 for La(Ni1−xZnx)2Si2. For higher Zn-contents 0.25 ≤ x ≤ 0.55 the solutions adopt the CaBe2Ge2-type (P4/nmm). The investigations are backed by single crystal X-ray diffraction data for Ce(Ni0.61Zn0.39)2Si2 (P4/nmm; a = 0.41022(1) nm, c = 0.98146(4) nm; RF = 0.012) and by Rietveld refinement for La(Ni0.56Zn0.44)2Si2 (P4/nmm; a = 0.41680(6) nm, c = 0.99364(4) nm; RF = 0.043). Interestingly, the Ce–Zn–Si system contains a ternary phase CeZn2(Si1−xZnx)2 of the ThCr2Si2 structure type (0.25 ≤ x ≤ 0.30 at 600 °C), which forms peritectically at T = 695 °C but does not include the composition “CeZn2Si2”. The primitive high temperature tetragonal phase with the CaBe2Ge2-type has also been observed for the first time in the Ce–Ni–Si system at CeNi2+xSi2−x, x = 0.33 (single crystal data, P4/nmm; a = 0.40150(2) nm, c = 0.95210(2) nm; RF = 0.0163). Physical properties (from 400 mK to 300 K) including specific heat, electrical resistivity and magnetic susceptibility have been elucidated for Ce(Ni0.61Zn0.39)2Si2 and La(Ni0.56Zn0.44)2Si2. Ce(Ni0.61Zn0.39)2Si2 exhibits a Kondo-type ground state. Low temperature specific heat data of La(Ni0.56Zn0.44)2Si2 suggest a spin fluctuation scenario with an enhanced value of the Sommerfeld constant.
| Type: | Article |
|---|---|
| Title: | BaAl₄ derivative phases in the sections {La,Ce}-Ni₂Si₂-{La,Ce}Zn₂Si₂: phase relations, crystal structures and physical properties |
| Location: | England |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1039/c5dt04705f |
| Publisher version: | https://doi.org/10.1039/c5dt04705f |
| Language: | English |
| Additional information: | © The Author(s), 2025. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. https://creativecommons.org/licenses/by/3.0/ |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10211360 |
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