Structural and magnetic properties in the polymorphs of CeRh{sub 0.5}Ge{sub 1.5}

Journal Article · Tue Apr 01 00:00:00 EDT 2014 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2014.01.015· OSTI ID:22334166

Kalsi, Deepti; Subbarao, Udumula ^[1]; Rayaprol, Sudhindra ^[2]

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1. New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore-560064 (India)
2. UGC-DAE Consortium for Scientific Research, R-5 Shed, B.A.R.C Campus, Trombay, Mumbai-400085 (India)

We investigate the structural and magnetic properties in the polymorphs of a new compound CeRh{sub 0.5}Ge{sub 1.5}. Depending upon the starting materials, and the slightly different synthesis method, we find that CeRh{sub 0.5}Ge{sub 1.5} compound exists in two different space groups. The first compound, α-CeRh{sub 0.5}Ge{sub 1.5} crystallizes in tetragonal α-ThSi{sub 2} structure type in space group I4{sub 1}/amd with lattice parameters, a=4.2034(6) Å and c=14.770(3) Å. In this structure, the cerium atoms occupy the position between the Rh/Ge tetrahedral layers. On the other hand, the second compound, namely β-CeRh{sub 0.5}Ge{sub 1.5} crystallizes in the AlB{sub 2} type hexagonal structure in space group P6/mmm, with lattice parameters, a=4.2615(7) Å and c=4.1813(9) Å. The crystal structure of β-CeRh{sub 0.5}Ge{sub 1.5} consists of two dimensional Rh/Ge hexagonal units and the cerium atoms are sandwiched between them. Magnetization studies exhibit magnetic ordering, as evident from a sharp peak in the plot of magnetic susceptibility measured as a function of temperature in a fixed magnetic field, in α-CeRh{sub 0.5}Ge{sub 1.5} and β-CeRh{sub 0.5}Ge{sub 1.5} at 3.6 K and 12 K, respectively. Structural and magnetic properties of both compounds are presented and discussed here. - Graphical abstract: Two polymorphs of a new compound CeRh{sub 0.5}Ge{sub 1.5} in the α-ThSi{sub 2} and AlB{sub 2} structure types were synthesized by arc melting. The magnetic measurements of both CeRh{sub 0.5}Ge{sub 1.5} phases suggest spin-glass behavior. - Highlights: • A new compound CeRh{sub 0.5}Ge{sub 1.5} in two difference phases was synthesized by arc melting. • The crystal structure of both compounds was determined from the single crystal XRD. • Isothermal relaxation measurements suggesting spin-glass like anomalies in both phases.

• OSTI ID: 22334166
• Journal Information: Journal of Solid State Chemistry, Vol. 212; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
HEXAGONAL LATTICES
LATTICE PARAMETERS
MAGNETIC FIELDS
MAGNETIC SUSCEPTIBILITY
MAGNETIZATION
MONOCRYSTALS
SPACE GROUPS
SPIN GLASS STATE
SYNTHESIS
TEMPERATURE DEPENDENCE
TETRAGONAL LATTICES
X-RAY DIFFRACTION