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nr 1
139-144
EN
The magnetic data for R_5Rh_4Ge_{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.
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nr 4
603-606
EN
The magnetic and magnetocaloric properties of Sm_{1-x}Gd_{x}Mn_{2}Ge_{2} compounds with 0 ≤ x ≤ 0.10 have been studied. SmMn_{2}Ge_{2} is antiferromagnetic below the Néel temperature T_{N} ( ≈ 400 K). Further cooling leeds to canted ferromagnetic phase below T_C = 341 K. With decreasing temperature, two metamagnetic phase transitions are observed: F2-AF1 at T_2 = 153 K and AF1-F1 at T_1 = 106 K. The maximum values of magnetic entropy change | Δ S_m | are found to be 1.5 J K^{-1} kg^{-1} at T_{1} and 2.0 J K^{-1} kg^{-1} at T_{2} in SmMn_{2}Ge_{2}. The MCE is found to increase with Gd concentration, | Δ S_{m}(T_{1}) | = 3.3 J K^{-1} kg^{-1}, while | Δ S_{m}(T_{2})| is slightly enhanced for x = 0.1. The magnetocaloric effect is found to be positive at T_{1} and negative at T_{2}.
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Content available remote Magnetism and Specific Heat of TmRhX (X = Ga, Ge) Compounds
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nr 6
998-1001
EN
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.
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Content available remote Magnetic Structures of Ho_5Rh_4Ge_{10}
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nr 6
1002-1004
EN
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.
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Content available remote Magnetocaloric Effect and Transition Order in HoAl
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nr 3
815-817
EN
Magnetic measurements of HoAl_{2} are reported. The compound crystallizes in the cubic MgCu_{2}-type crystal structure. HoAl_{2} exhibits two successive magnetic transitions: below T_{c} = 29 K a ferromagnetic order is formed while anomaly at T_{t} = 20 K is related to reorientation of magnetic moment. Near transition temperatures a magnetocaloric effect with magnetic entropy changes -ΔS_{m} equal to 6.3 J/(mol K) at T_{c} and 5.0 J/(mol K) at T_{t} for an external field μ_{0}H = 9 T is observed.
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Content available remote Magnetic Properties of Ho_{5}Ni_{2}In_{4}
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EN
X-ray diffraction and magnetic measurements of Ho_{5}Ni_{2}In_{4} are reported. This compound crystallizes in the orthorhombic Lu_{5}Ni_{2}In_{4}-type structure. Magnetic data indicate ferromagnetic properties below T_c = 30 K.
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Content available remote Magnetic Properties and Magnetic Structure of DyCoSi_2 Compound
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nr 5
1176-1178
EN
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) μ_{B} are smaller than free Dy^{3+} ion value (10.0 μ_{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.
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Content available remote Crystal Structure and Magnetic Properties of Tb_{11}O_{20}
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nr 1
98-100
EN
Magnetic and neutron diffraction data for Tb_{11}O_{20} compound are reported. This compound crystallizes in a triclinic crystal structure described by the space group P1 and is antiferromagnetic with the Néel temperature 5.1 K.
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Content available remote Magnetic Properties RNi_5Sn (R = Pr, Nd) Compounds
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EN
X-ray diffraction and magnetic measurements of RNi_5Sn (R = Pr, Nd) compounds are reported. These compounds crystallize in the hexagonal CeNi_5Sn-type structure. Magnetic data indicate that both compounds are antiferromagnet with the Néel temperatures T_{N} equal to 24 K (R = Pr) and 8.8 K (R = Nd). The magnetic data below T_{N} suggest the complex magnetic order.
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Content available remote Neutron Diffraction Studies of Nanoparticle DyMnO_3 Compound
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EN
The neutron powder diffraction (NPD) measurements of the nano-size DyMnO_3 manganite have been performed. The obtained results indicate that this compound crystallizes in the orthorhombic crystal structure described by the space group Pnma. The Mn and Dy moments order antiferromagnetically at different temperatures and form modulated magnetic structure described by the propagation vector k=(k_x, 0, 0) with the different values of k_x component for the Mn and Dy sublattices. The values of k_x component for Mn sublattice increase with decreasing of the temperature and are smaller that in bulk compound. The wide Bragg peaks related to the Dy sublattice suggest that the magnetic order in this sublattice has the cluster-like character.
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Content available remote Magnetic Ordering in ErFe_{0.3}Ge_{2} and ErNi_{0.65}Ge_{2} Compounds
71%
EN
The magnetic ordering in ErFe_{0.3}Ge_{2} and ErNi_{0.65}Ge_{2} compounds crystallizing in the orthorhombic structure of the CeNiSi_{2}-type has been investigated by neutron diffraction and magnetic measurements. The Er magnetic moments have been found to order antiferromagnetically below 2.5 K in ErFe_{0.3}Ge_{2} and 2.3 K in ErNi_{0.65}Ge_{2}. The magnetic structure of the former compound can be described by the propagation vector k = (0.044(1), 0, 0.384(1)). The Er magnetic moments are aligned along the a-axis and alternate with the sequence ++- in the unit cell. At 1.5 K they are equal to 5.9(1) μ_{B}. In contrast, the magnetic unit cell of ErNi_{0.65}Ge_{2} has been established to be equal to the chemical one. The magnetic moments in this compound are arranged in a collinear manner pointing along the a-axis with the sequence +-+-. The Er moment value measured at 1.5 K is 2.90(8) μ_{B}.
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Content available remote Magnetic Properties of RSn_{2} (R = Tb, Dy) Compounds
71%
EN
Polycrystalline samples of TbSn_{2} and DySn_{2} were studied by means of magnetic susceptibility, electrical resistivity and heat capacity measurements. Both compounds have been found to order antiferromagnetically at low temperatures with some extra features in the ordered state due to changes in their magnetic structures. The two stannides exhibit metallic conductivity. The estimated crystal field levels splitting of Tb^{3+} and Dy^{3+} ground multiplets do not exceed 75 K.
EN
X-ray diffraction and magnetic measurements of R_2Ni_{2 - x}In (R = Ho, Dy, x = 0.3 and R = Gd, Tb, Er, x = 0.22) compounds are reported. The compounds crystallize in the tetragonal Mo_2FeB_2-type crystal structure (space group P4/mbm). Magnetic measurements reveal antiferromagnetic order with the Néel temperatures T_{N} equal to 26.4 K (Gd), 20.2 K (Tb), 8.3 K (Dy), 7.1 K (Ho), and 6.3 K (Er). For R = Gd, Tb and Er an additional phase transition below T_{N} is observed at 13.5, 13.1, and 5.0 K, respectively.
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Content available remote Neutron Diffraction Studies of Tb_2Ni_{2-x}In Intermetallic Compounds
61%
EN
The magnetic ordering of the Tb_2Ni_{1.78}In and Tb_2Ni_2In have been studied by neutron diffraction measurements. Tb_2Ni_{1.78}In with the tetragonal Mo_2FeB_2-type (space group P4/mbm, tP10) is antiferromagnet with the Néel temperature equal to 20 K. Below this temperature Tb moments form collinear magnetic structure commensurate with the crystal, described by the propagation vectors equal to (1/4, 1/4, 1/2). Magnetic moment equal to 7.60(6) μ_{B} is parallel to c-axis. The Tb_2Ni_2In in the orthorhombic Mn_2 lB_2-type (space group Cmmm, oC10) was detected as an impurity in the studied sample. It orders antiferromagnetically below ≈ 100 K with collinear moment arrangement described by the propagation vector (1/2, 1/2, 1/2). t 1.6 K μ_{Tb} = 6.33(14) μ_{B} and is parallel to the c-axis.
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Content available remote Magnetic Properties of Hexagonal RTIn Rare-Earth Intermetallics with Frustration
61%
EN
Magnetic properties, including magnetic structure, of some RTIn compounds (R = Tb-Er; T = Cu, Ni, Pd, Pt, Au) with the hexagonal ZrNiAl-type crystal structure are reported. Distribution of the rare earth atoms in the basal plane is similar to the kagomé-lattice. Magnetic moments are localized exclusively on the rare earth atoms and form different types of magnetic ordering. Experimental results are analyzed within the Ruderman-Kittel-Kasuya-Yosida and crystal electric field frames. Monte Carlo simulations, including the J_{1} and J_{2} exchange integrals between nearest and next nearest spins and Dzialoshinsky-Moriya interaction, were performed resulting in a number of magnetic phases, some of which are in good agreement with the magnetic ordering determined in the neutron diffraction experiments.
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Content available remote Magnetic Properties of the Nanocrystalline DyMnO_{3} Compound
51%
EN
We report on the X-ray powder diffraction and magnetic measurements of the polycrystalline and the two nanocrystalline samples of DyMnO_{3} compound synthesized at temperatures of 800 and 850°C. All samples at room temperature crystallize in the orthorhombic crystal structure (space group Pnma). The crystal structure parameters determined change only slightly with preparation methods but the average grains size of the nanoparticles determined from X-ray data increases significantly with increasing annealing temperature. Temperature dependence of the magnetic susceptibility indicates the antiferromagnetic order in Dy sublattice at low temperatures.
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