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We present the study of structural and electronic properties in tetragonal R CuAl 3− x Ga x solid solutions (where R = Ce, La), based on X-ray diffraction, magnetization, ac-susceptibility, specific heat and electrical resistivity measurements. The development of lattice parameters with Ga content shows a clear change between concentrations with x < 1 and x > 1. All studied materials order magnetically with the ordering temperature around 2 K. The specific heat analysis leads to estimation of the energy splitting between the ground state and the first excited crystal field level. The splitting increases with increasing Ga content. The magnetoresistance measurements reveal strong ferromagnetic correlations in paramagnetic state, at least in Ga rich part of the series. [ABSTRACT FROM AUTHOR]

The magnetization and electrical resistivity measurements on a CePdIn single crystal as well as its preparation and structural characterization are presented. The negative paramagnetic Curie temperatures indicate antiferromagnetic ground state, the anisotropy of the paramagnetic Curie temperature amounts 22.7 K. No ferromagnetic correlations were indicated. Powder neutron diffraction experiment performed at temperatures down to 0.4 K did not lead to observation of any magnetic peak in diffraction patterns. We estimate the magnetic moment on Ce atoms to be significantly lower than 0.5 μB. The temperature development of lattice parameters documents the standard thermal expansion of the unit cell; no signs of structural phase transition were observed. [ABSTRACT FROM AUTHOR]

Abstract: The magnetization, specific heat, electrical resistivity and magnetoresistance were measured on compounds. The increase of structure parameters with substitution of Cu by larger atoms of Au was observed. Such a substitution causes a decrease of the Néel temperature as well as the Kondo temperature. The strong ferromagnetic correlations were found in the series, at least in the gold rich compounds. Nevertheless, all the compounds order antiferromagneticaly and no further phase transition was observed. The La counterparts were investigated by means of electrical resistivity and their basic physical properties are presented as well. [Copyright &y& Elsevier]

Highlights: [•] CePd2(Al,Ga)2 series and La counterparts were prepared and characterized. [•] Magnetization and electrical resistivity measurements were provided on prepared samples. [•] The powder neutron diffraction experiment was performed on CePd2Ga2 compound. [•] Structural transition from tetragonal structure to lower symmetric one was observed. [•] Hypothesis about the development of structural transition are introduced. [ABSTRACT FROM AUTHOR]

We have investigated the effect of hydrostatic pressure on magnetic properties of TbNiAl, crystallizing in hexagonal ZrNiAl-type structure. TbNiAl orders antiferromagnetically below TN = 45 K and undergoes further magnetic phase transition to another AF phase at T1 = 23 K. The magnetic field of Bc ≅= 0:3 T applied along the c-axis at 2 K leads to the transition to ferromagnetic order. By applying the hydrostatic pressure, both TN and T1 remain almost unaffected whereas Bc shows a strong increase. The hydrostatic pressure stabilizes the antiferromagnetic state which can be related to development of structural parameters. [ABSTRACT FROM AUTHOR]

The superconductivity in LaPd2Al2−xGax compounds was studied by means of electrical resistivity and specific heat measurements. The concentration development of the superconducting properties was revealed. The measured data deviate significantly from the Bardeen–Cooper–Schrieffer theory predictions and are discussed in the context of unconventional superconductivity. The electronic specific heat below follows almost quadratic temperature dependence, which might indicate an axial state with line nodes in the superconducting gap structure. [ABSTRACT FROM AUTHOR]

A Ce 2 Pd 2 In single crystal was synthesized employing the Czochralski growth method from a stoichiometric melt. It was found to crystallize in the tetragonal Mo 2 FeB 2 -type structure. The investigation by means of X-ray diffraction, magnetization, specific heat, and electrical resistivity measurements revealed two successive magnetic phase transitions at around 4.5 and 4.1 K in the possibly slightly off-stoichiometric (Pd rich) crystal. Ferromagnetic ground state changes into the paramagnetic state through an intermediate antiferromagnetic phase. The measured magnetization and specific heat data were discussed in the view of first principles calculations of crystal field for Ce 2 Pd 2 In. Uniaxial magnetic anisotropy confining Ce moments into the c -axis has rather high energy exceeding 5 meV. Full ordered Ce-4 f 1 moments 2.14 μ B do not indicate any Kondo-type interaction, no many body enhancement of the Sommerfeld coefficient can be deduced. [ABSTRACT FROM AUTHOR]

CePd 2 Al 2 single crystal was investigated by means of magnetization, specific heat and electrical resistivity measurements including the resistivity measurement under hydrostatic pressure. The antiferromagnetic phase transition with Néel temperature of 2.7 K was confirmed by all types of measurements as well as the first order structural phase transition from tetragonal to orthorhombic structure around 13 K. The long-range magnetic order with magnetization easy basal-plane was found. The thorough analysis of magnetization and specific heat was done to discuss the results in context of previous inelastic neutron scattering experiment and the crystal-field scheme. The electrical resistivity under hydrostatic pressure revealed a shift of the structural transition to the higher temperatures, while the magnetic transition temperature remains constant. The resistivity behavior at the structural transition indicates a change of the low-temperature crystal structure in pressures above 0.6 GPa. [ABSTRACT FROM AUTHOR]

Highlights: [•] We have studied structural and magnetic properties of TbNiAl single crystal. [•] We have studied properties of TbNiAl under uniaxial and hydrostatic pressure. [•] The uniaxial pressure (along c-axis) leads towards the ferromagnetic order. [Copyright &y& Elsevier]

Our study is focused on superconductivity in LaPt 2 Al 2 compound. Specific heat and electrical resistivity measurements reveal a superconducting state below 0.57 K. Superconducting behaviour is in agreement with the weak coupling limit of BCS theory. The electronic Sommerfeld coefficient and equilibrium volume were described by first principles methods. The calculated electron phonon constant, λ = 0.48 , using the McMillan formula is small. The crystal lattice of LaPt 2 Al 2 is described by the orthorhombic space group C m m e. Polarisation contrast microscopy reveals a domain structure, which is the result of a symmetry lowering structural transition above room temperature. • The superconducting state was found in LaPt 2 Al 2 below 0.57 K. • The superconducting behaviour is in agreement with Bardeen–Cooper–Schrieffer theory. • The domain structure suggests structural transition above the room temperature. [ABSTRACT FROM AUTHOR]