Structural Aspects of Chemical Bonding in RTX Intermetallic Compounds

Unit cell dimensions of ternary RTX intermetallic compounds (R = rare earth metal, T = »nd« transition metal and X = Si, Ge or Sn) are analyzed with respect to the atomic radius of the rare earth component. On the basis of the crystal structure data, information is given on the Chemical bonding in these phases

Magnetic properties of RIrSi (R = Tb, Dy, and Ho) compounds

The magnetic data for the polycrystalline samples of RIrSi (R = Tb, Dy and Ho) compounds are reported. These compounds are antiferromagnets with the Néel temperatures equal to 32 K (R = Tb), 7.0 K (R = Dy) and 4.8 K (R = Ho), respectively. The external magnetic field induces the one step for TbIrSi and two step for DyIrSi and HoIrSi metamagnetic phase transitions. The values of the critical field as Néel temperatures decrease with increase of the number of 4f electrons. The magnetic phase diagrams (H, T) are determined

Magnetic properties and the magnetic phase transitions in R5Rh4Ge10R_{5}Rh_{4}Ge_{10} (R = Tb-Tm) compounds

The magnetic data for $R_{5}Rh_{4}Ge_{10}$ (R = Tb, Dy, Ho, Er, and Tm) compounds was investigated by means of the dc magnetization and dc and ac magnetic susceptibility. At low temperature all these compounds are antiferromagnets. For these with R = Tb, Ho and Er below $T_{N}$ the additional phase transitions are observed. The obtained data are compared with the neutron diffraction results

Magnetic and related properties of ternary TmTX intermetallics

We report on the magnetic and thermal properties of a few TmTX compounds, where T = d-electron metal and X = p-electron element. In all these ternaries but TmRuGe the thulium magnetic moments order antiferro- or ferromagnetically at low temperatures. The specific heat data confirms the magnetic orderings and reveals the influence of crystalline electric field effects

Structural Aspects of Chemical Bonding in RTX Intermetallic Compounds

Unit cell dimensions of ternary RTX intermetallic compounds (R = rare earth metal, T = »nd« transition metal and X = Si, Ge or Sn) are analyzed with respect to the atomic radius of the rare earth component. On the basis of the crystal structure data, information is given on the Chemical bonding in these phases

Magnetism and specific heat of TmRhX (X = Ga, Ge) compounds

Magnetic and specific heat data of the TmRhX (X = Ga, Ge) compounds are reported. These compounds crystallize in an orthorhombic crystal structure of the TiNiSi-type (space group Pnma). Magnetic data indicate that the compounds are antiferromagnets with the Néel temperature $T_{N}$ equal to 3.9 K for TmRhGa and 6.0 K for TmRhGe. Magnetic susceptibility of TmRhGe has an additional peak at $T_{t}$ = 10.6 K. In TmRhGe temperature dependence of χ"(T), the positions of both the peaks at $T_{N}$ and $T_{t}$ change with frequency indicating a relaxation process. These data suggest that with the decreasing temperature, first a cluster glass state and next the long-range aniferromagnetic order exists

Magnetic properties and magnetic structure of DyCoSi_{2} compound

The results of new magnetic dc and neutron diffraction measurements of $DyCoSi_{2}$ compound are presented. Below $T_{N}$ equal to 10.9 K the Dy moments form collinear G-type structure with the moment parallel to the c-axis. The value of Dy-moment equal to $5.5(2) _{\mu B}$ are smaller than free $Dy^{3+}$ ion value ($10.0 _{\mu B}$). These and the three-step magnetization process indicate the strong influence of the crystal electric field on the stability of the magnetic order. Increase of the values of the lattice parameters at 1.5 K in reference of these at 20 K indicate magnetostriction effect at low temperatures

Electronic structure and thermodynamic properties of RNi_{5}Sn (R = La, Ce, Pr, Nd) compounds

The electronic structure, pressure and temperature dependence of thermodynamic properties of RNi5Sn (R = La, Ce, Pr, Nd) compounds are calculated by ab initio full potential local orbital minimum-base(ver. 9 and ver. 14) method. These compounds crystallize in the hexagonal crystal structure (space group P6c/mmc, No. 194). The band calculations were performed in the scalar-relativistic mode for the exchange correlation potentials in the form: of the Perdew-Burke-Ernzerhof general gradient approximation. In this work we present the band structures of LaNi5Sn, CeNi5Sn, NdNi5Sn and PrNi5Sn compounds. The thermodynamic properties (bulk modulus, Debye temperature) are calculated in the Debye-Grüneisen model using the equation of states in the form of Birch-Murnaghan, Poirier-Tarantola and Vinet. Our results have shown that values of thermodynamic properties depend on the method of calculations

Magnetic structures of Ho5Rh4Ge10Ho_{5}Rh_{4}Ge_{10}

A powder diffraction measurement of $Ho_5Rh_4Ge_{10}$ is reported. This compound crystallizes in the tetragonal $Sc_5Co_4Si_{10}$-type structure (space group P4/mbm) in which the Ho atoms occupy three different sites. The neutron diffraction measurements indicate antiferromagnetic order with the Néel temperature $T_{N}$=7 K. Below $T_{N}$ an additional phase transition at 4.5 K connected with the change of the magnetic structure is observed. The Ho moments in 4(h) site form collinear order up to T_{N} while moments at 2(a) site form sine modulated structure. Determined experimentally magnetic structures are compared to the results of symmetry analysis