BaAl<sub>4</sub> Derivative Phases in the Sections {La,Ce}Ni<sub>2</sub>Si<sub>2</sub>-{La,Ce}Zn<sub>2</sub>Si<sub>2</sub>
- Autor(en)
- Fainan Failamani, Zahida Malik, Leonid P. Salamakha, Friedrich Kneidinger, Andrij Grytsiv, Herwig Michor, Ernst Bauer, Gerald Giester, Peter Franz Rogl
- Abstrakt
Phase relations and crystal structures have been evaluated within the sections LaNi
2Si
2-LaZn
2Si
2 and CeNi
2Si
2-CeZn
2Si
2 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 "LaZn
2Si
2" or "CeZn
2Si
2", solid solutions {La,Ce}(Ni
1-xZn
x)
2Si
2 exist with the Ni/Zn substitution starting from {La,Ce}Ni
2Si
2 (ThCr
2Si
2-type; I4/mmm) up to x = 0.18 for Ce(Ni
1-xZn
x)
2Si
2 and x = 0.125 for La(Ni
1-xZn
x)
2Si
2. For higher Zn-contents 0.25 ≤ x ≤ 0.55 the solutions adopt the CaBe
2Ge
2-type (P4/nmm). The investigations are backed by single crystal X-ray diffraction data for Ce(Ni
0.61Zn
0.39)
2Si
2 (P4/nmm; a = 0.41022(1) nm, c = 0.98146(4) nm; R
F = 0.012) and by Rietveld refinement for La(Ni
0.56Zn
0.44)
2Si
2 (P4/nmm; a = 0.41680(6) nm, c = 0.99364(4) nm; R
F = 0.043). Interestingly, the Ce-Zn-Si system contains a ternary phase CeZn
2(Si
1-xZn
x)
2 of the ThCr
2Si
2 structure type (0.25 ≤ x ≤ 0.30 at 600 °C), which forms peritectically at T = 695 °C but does not include the composition "CeZn
2Si
2". The primitive high temperature tetragonal phase with the CaBe
2Ge
2-type has also been observed for the first time in the Ce-Ni-Si system at CeNi
2+xSi
2-x, x = 0.33 (single crystal data, P4/nmm; a = 0.40150(2) nm, c = 0.95210(2) nm; R
F = 0.0163). Physical properties (from 400 mK to 300 K) including specific heat, electrical resistivity and magnetic susceptibility have been elucidated for Ce(Ni
0.61Zn
0.39)
2Si
2 and La(Ni
0.56Zn
0.44)
2Si
2. Ce(Ni
0.61Zn
0.39)
2Si
2 exhibits a Kondo-type ground state. Low temperature specific heat data of La(Ni
0.56Zn
0.44)
2Si
2 suggest a spin fluctuation scenario with an enhanced value of the Sommerfeld constant.
- Organisation(en)
- Institut für Materialchemie, Institut für Mineralogie und Kristallographie
- Externe Organisation(en)
- Technische Universität Wien, Christian Doppler Forschungsgesellschaft
- Journal
- Dalton Transactions
- Band
- 45
- Seiten
- 5262-5273
- Anzahl der Seiten
- 12
- ISSN
- 1477-9226
- DOI
- https://doi.org/10.1039/c5dt04705f
- Publikationsdatum
- 03-2016
- Peer-reviewed
- Ja
- ÖFOS 2012
- 104017 Physikalische Chemie, 104011 Materialchemie, 105113 Kristallographie
- Schlagwörter
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/baal4-derivative-phases-in-the-sections-laceni2si2lacezn2si2(95982e82-770c-4aeb-9d0c-dcda02899af7).html