J.K. Yakinthos

Magnetic properties of the ternary rare earth silicides R2PdSi3 (R = Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm and Y)

Abstract The magnetic properties of R 2 PdSi 3 compounds, where R is Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm and Y, have been investigated from 4.2 to 300 K. Pr 2 PdSi 3 does not show any magnetic ordering temperature down to 4.2 K. Nd 2 PdSi 3 is ferromagnetic with a Curie temperature of 16 K. The heavy rare earth compounds show magnetic ordering temperatures in the region between 8 and 21 K, except the compound with Tm for which the ordering temperature must be lower than 4.2 K. Y 2 PdSi 3 is a nonmagnetic compound.

Magnetic characteristics of some RNiSn (R = Ce, Pr, Nd, Sm) and RRhSn (R = Ce, Pr, Nd) compounds

Abstract Magnetic properties of seven equiatomic ternary RNiSn and RRhSn compounds (R = light rare earth) have been studied in fields of up to 20 kOe in the temperature range 4.2–200 K. It has been found that all compounds follow the Curie-Weiss law above 40 K, except CeNiSn and CeRhSn which do not show Curie-Weiss behavior at any temperature. The latter show a Kondo or valence fluctuation behavior. The compound SmNiSn orders antiferromagnetically with a Neel temperature ≃ 9 K. No ordering temperature was observed down to 4.2 K for the rest of the compounds.

Magnetic properties of the ternary carbides of the rare earth and nickel group metals

Abstract The magnetic properties of the RNiC2 compounds (R  Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm and Y) have been investigated. It was found that the compounds for which R  Nd, Gd, Tb, Dy, Er and Tm show ordering temperatures between 7 K (Nd) and 25 K (Tb). PrNiC2 and HoNiC2 do not show any ordering temperature down to 4.2 K. YNiC2 shows a temperature-independent susceptibility. None of the compounds follows the Curie-Weiss law in the temperature region 4.2 – 250 K.

MAGNETIC PROPERTIES OF THE EQUIATOMIC TERNARY RTSN COMPOUNDS (R=RARE EARTH, T=PT, RH)

Abstract Magnetic susceptibility studies on the hexagonal ternary equiatomic RTSn (R = rare earth and Y; T = Pt, Rh) compounds have been realized. These compounds are isostructural to Fe2P with space group P 6 2m. The ordering temperatures of all compounds are smaller than 19 K. The susceptibility of YTSn is temperature independent.

Magnetic properties of ternary TCo2Si2 compounds (T Gd, Tb, Dy, Ho, Er, Y)

Abstract The magnetic susceptibilities of six TCo 2 Si 2 ternary compounds ( T  Gd , Tb , Dy , Ho , Er , Y ) are reported from 300 to 4.2 K. These compounds crystallize in the tl 10 ThCu 2 Si 2 structure with space group I 4/ mmm . Their Curie paramagnetic temperatures are negative. The compounds with gadolinium, dysprosium and erbium are antiferromagnetic with Neel tempertures between 6 and 44 K. The terbium and holmium compounds seem to be ferromagnetic with Curie temperatures of 8 and 15 K respectively. YCo 2 Si 2 does not seem to have any magnetic moment.

Magnetic structure of the TbNiC2 ternary carbide

Abstract The magnetic structure of the TbNiC 2 ternary carbide was studied by neutron diffraction. The crystal structure of this compound is orthorhombic, space group Amm2, with Neel temperature equal to 25 K. The magnetic cell, at 16 K, is four times larger than the chemical one, with a wave vector k = [ 1 2 1 2 0] . The terbium moment value and direction are μ Tb = 6.8μ B along the c -axis of the crystal. The crystal field calculations on the Tb 3+ site with a molecular field parallel to c , give a magnetic model which agrees with the observed one.

Magnetic characteristics of some RNiSn ternary equiatomic alloys

Abstract Magnetic properties of seven equiatomic ternary RNiSn compounds (R = heavy rare earth and Y) have been studied in fields of up to 20 kOe in the temperature range 4.2–200 K. It has been found that all compounds, which belong to the orthorhombic TiNiSi-type structure, are paramagnetic above 40 K. YNiSn presents a temperature-independent susceptibility and the moment of nickel was found to be zero in the whole series. The compounds with Gd, Tb and Dy are antiferromagnetic at low temperatures. No ordering temperature was observed down to 4.2 K for the compounds with Ho, Er and Tm.

The antiferromagnetic structures of TbCu2Ge2 and HoCu2Ge2 by neutron diffraction

Abstract The magnetic structures of TbCu 2 Ge 2 and HoCu 2 Ge 2 were studied by neutron diffraction. At 293 K the chemical structure is tetragonal body centered, space group I 4/ mmm . The magnetic cell at 4.2 K is four times larger than the chemical one with a wave vector k = 1 2 0 1 2 . The magnetic space group is triclinic P a 1 (Sh 2 7 ) for both compounds. The moment values and directions are μ Tb = 8.48(6) [ μ B ] along [110] tetr. and μ HO = 6.5(1)[ μ B ] making an angle of 81.4(°) with c and 80(°) with a 1 . The structure consists of ferromagnetic (101) layers stacked antiferromagnetically.

Magnetic structure determination of NdNiC2 and TmNiC2 by neutron diffraction

Isostructural orthorhombic NdNiC2 and TmNiC2 reveal collinear antiferromagnetic structures with magnetic propagation vectors [12120] and [0, 0, 1], respectively. In NdNiC2, ferromagnetic (110) planes are coupled pairwise in opposite spin orientations; in TmNiC2, adjacent ferromagnetic (001) planes are coupled antiferromagnetically. The magnetic moments are oriented parallel to the a-axis and have values of 2.7μB (Nd) and 3.3μB (Tm) at 4 K.

The magnetic structure of Er5Si3

Abstract Neutron-diffraction measurements were performed on Er 5 Si 3 in the temperature range between 1.8 and 120K. The compound crystallizes in the hexagonal Mn 5 Si 3 -type structure. The temperature variation of the 010 intensity shows a Neel temperature equal to 20 K. The erbium magnetic moments are 8.3 μ B for site 4d and 5.2 μ B for site 6g. The magnetic moments of both sites lie on the (b, c) plane forming an angle of 30 ° with the c -axis.