Neutron diffraction studies of RSn{sub 1+x}Ge{sub 1-x} (R=Tb-Er) compounds

Journal Article · Fri Jul 15 00:00:00 EDT 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2011.04.040· OSTI ID:21580165

Gil, A ^[1]; Penc, B; Baran, S ^[2]; Hoser, A ^[3]; Szytula, A ^[2]

---

1. Department of Mathematics and Natural Sciences, J. Dlugosz University Czestochowa, Armii Krajowej 13/15, PL 42-200 Czestochowa (Poland)
2. M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, PL 30-059 Krakow (Poland)
3. BENSC, Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, D 14109 Berlin (Germany)

The magnetic structures of RSn{sub 1+x}Ge{sub 1-x} (R=Tb, Dy, Ho and Er, x{approx}0.1) compounds have been determined by neutron diffraction studies on polycrystalline samples. The data recorded in a paramagnetic state confirmed the orthorhombic crystal structure described by the space group Cmcm. These compounds are antiferromagnets at low temperatures. The magnetic ordering in TbSn{sub 1.12}Ge{sub 0.88} is sine-modulated described by the propagation vector k=(0.4257(2), 0, 0.5880(3)). Tb magnetic moment equals 9.0(1) {mu}{sub B} at 1.62 K. It lies in the b-c plane and form an angle {theta}=17.4(2) deg. with the c-axis. This structure is stable up to the Neel temperature equal to 31 K. The magnetic structures of RSn{sub 1+x}Ge{sub 1-x}, where R are Dy, Ho and Er at low temperatures are described by the propagation vector k=(1/2, 1/2, 0) with the sequence (++-+) of magnetic moments in the crystal unit cell. In DySn{sub 1.09}Ge{sub 0.91} and HoSn{sub 1.1}Ge{sub 0.9} magnetic moments equal 7.25(15) and 8.60(6) {mu}{sub B} at 1.55 K, respectively. The moments are parallel to the c-axis. For Ho-compound this ordering is stable up to T{sub N}=10.7 K. For ErSn{sub 1.08}Ge{sub 0.92}, the Er magnetic moment equals 7.76(7) {mu}{sub B} at T=1.5 K and it is parallel to the b-axis. At T{sub t}=3.5 K it tunes into the modulated structure described by the k=(0.496(1), 0.446(4), 0). With the increase of temperature there is a slow decrease of k{sub x} component and a quick decrease of k{sub y} component. The Er magnetic moment is parallel to the b-axis up to 3.9 K while at 4 K and above it lies in the b-c plane and form an angle 48(3) deg. with the c-axis. In compounds with R=Tb, Ho and Er the magnetostriction effect at the Neel temperature is observed. - Graphical abstract: The magnetic structures of RSn{sub 1+x}Ge{sub 1-x} (R=Tb, Dy, Ho and Er, x{approx}0.1) compounds have been determined by neutron diffraction studies on polycrystalline samples. The magnetic ordering in TbSn{sub 1.12}Ge{sub 0.88} (a) is sine-modulated described by the propagation vector k=(0.426, 0, 0.588). The magnetic structures of RSn{sub 1+x}Ge{sub 1-x} where R are Dy (b), Ho (b) and Er (c) at temperatures close to 1.5 K are described by the propagation vector k=(1/2, 1/2, 0) with the sequence (++-+) of magnetic moments in the crystal unit cell. For Ho- and Dy-compound this ordering is stable up to T{sub N} while for Er-compound at T{sub t}=3.5 K it tunes into a modulated structure (d). Highlights: > We determine crystal and magnetic structures of RSn{sub 1+x}Ge{sub 1-x} (R=Tb, Dy, Ho, Er, x{approx}0.1) compounds. > We compare the results with those for RT{sub x}X{sub 2} (X=Ge, Sn) compounds. > We examine the influence of other components (T, Sn, Ge) on magnetic ordering in R-sublattices. > Magnetic ordering in RSn{sub 1+x}Ge{sub 1-x} compounds is similar to those observed in RT{sub x}X{sub 2} compounds. > Other elements (T, Sn, Ge) have not got significant influence on stability of magnetic ordering.

• OSTI ID: 21580165
• Journal Information: Journal of Solid State Chemistry, Vol. 184, Issue 7; Other Information: DOI: 10.1016/j.jssc.2011.04.040; PII: S0022-4596(11)00221-0; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
DYSPROSIUM COMPOUNDS
ERBIUM COMPOUNDS
HOLMIUM COMPOUNDS
INDIUM COMPOUNDS
INTERMETALLIC COMPOUNDS
MAGNETIC MOMENTS
MAGNETIZATION
MAGNETOSTRICTION
NEEL TEMPERATURE
NEUTRON DIFFRACTION
ORTHORHOMBIC LATTICES
PARAMAGNETISM
POLYCRYSTALS
RARE EARTHS
SPACE GROUPS
STABILITY
TEMPERATURE RANGE 0065-0273 K
TIN COMPOUNDS
VECTORS
ALLOYS
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTALS
DIFFRACTION
ELEMENTS
MAGNETIC PROPERTIES
MAGNETISM
METALS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
SCATTERING
SYMMETRY GROUPS
TEMPERATURE RANGE
TENSORS
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE