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A versatile type of non-magnetic uniaxial pressure cell has been designed for magnetic measurements in SQUID magnetometer. An advanced technology of machining of miniature parts of the cell was used to make new type of an internal squeezer module, where a sample can be compressed by force up to 3 kN in direction perpendicular to external magnetic field. A correct operation of the cell was tested by study of magnetic behaviour of the Heusler off-stoichiometric Ni2MnSn alloy under uniaxial compression. An unexpected significant difference between reversible effects of uniaxial compression on magnetization of the austenite and martensite phases of the alloy is discussed. The uniaxial compression effects are compared with the effects of hydrostatic pressure on a coupling between magnetization and structural transformation of the alloy. [ABSTRACT FROM AUTHOR]

Single crystal of the stoichiometric Ni2MnSn alloy (cubic L21 crystal structure) was prepared by the Czochralski method. The values of the magneto-crystalline anisotropy constant K1 have been determined at temperature 10 K under ambient and high hydrostatic pressures, K1 = + 0.17 × 104 and +1.96 × 104 J/m3 (0.7 GPa), respectively. The pressure-induced decrease of magnetization was confirmed and hence the significant non-trivial increase of uniaxial anisotropy with increasing pressure points to a possible distortion of the cubic structure of the single crystal under hydrostatic pressure. Simultaneously, the more pronounced and pressure almost insensitive magneto-crystalline anisotropy, K1 = + 9.1 × 104 J/m3, has been observed in the martensite phase (orthorhombic structure) of the off-stoichiometric Ni2Mn1.43Sn0.57 alloy. The effect of a directional dependence of the Young modulus that was theoretically derived in the case of the Ni2MnSn-based alloys is discussed. [ABSTRACT FROM AUTHOR]

Structural and magnetic properties of the Shastry-Sutherland material Yb2Pt2Pb were studied in single-crystalline form under pressures up to 10 GPa, magnetic fields up to 17 T, and temperatures down to 0.3 K. Surprisingly robust magnetic order is observed with the Néel temperature TN = 2.1 K stable up to 8.1 GPa. Indication of an additional magnetic phase formation can be traced in resistivity data for magnetic field along the c-axis exceeding the (pressure-dependent) metamagnetic transition. The related anomaly shifts to higher temperatures with increasing field, merging TN at the tricritical point. Experiments with μ0H // [110] revealed the pressure stabilization of observed magnetic phases with respect to the magnetic field. The crystal-structure type is stable up to 10 GPa, without any sign of symmetry change, exhibiting moderate volume compressibility with bulk modulus B = 116(13) GPa, in good agreement with B = 118 GPa provided by the density functional theory. [ABSTRACT FROM AUTHOR]

In addition to complex spin-ice and spin-liquid states of rare-earth pyrochlore oxides, A 2 Ir 2 O 7 iridates have been recently proposed to host a cooling-field-controllable antiferromagnetic domain structure of iridium moments. Reliable and profound studies of the magnetic domain structure, including domains' interfaces, have been frequently limited by insufficient sample quality or lack of single crystals. We report the magnetic properties of the for-the-first-time synthesised Lu 2 Ir 2 O 7 and Er 2 Ir 2 O 7 single crystals; focussing on the robust ferromagnetic component of magnetisation present in the material with the antiferromagnetically ordered state of the all-in-all-out (AIAO) type. Anisotropy of the system, as well as the effects of magnetic (Er 3+ ) or nonmagnetic (Lu 3+ ) local environments on Ir 4+ moments, is studied. The size of the domains is calculated based on a simplified domain wall model. Results are discussed in the framework of AIAO and AOAI domains and interfaces on the geometrically frustrated lattice., (© 2024. The Author(s).)

Lattice and electronic properties of La 2 Pd 2 In were studied at ambient and elevated pressures so as to determine features related to a specific atomic coordination without any influence of magnetism. We describe temperature dependences of lattice parameters, heat capacity and electrical resistivity of single-crystalline La 2 Pd 2 In (s.g. P 4/ mbm ) in a broad temperature range 0.09-300 K. Together with the anisotropic effect of hydrostatic pressure, showing that the lattice is more compressible in the basal plane, we can conclude that the lattice is affected by degrees of freedom of the La atoms with positions not imposed by symmetry. The lattice anisotropy is smaller than that found for isostructural ferromagnet Ce 2 Pd 2 In. The equilibrium bulk modulus B 0 = (48 ± 3) GPa was determined on the basis of individual linear compressibilities. Measurement of electrical resistivity indicated a superconducting state below T = 0.59 K with a low critical field 0.005 T at T = 380 mK. The onset of superconducting state as a bulk property of La 2 Pd 2 In was confirmed by measurements of specific heat and AC magnetic susceptibility. Experimental data can be accounted by first-principles electronic-structure calculations based on density-functional theory. The measured Sommerfeld coefficient γ = 10.6 mJ mol -1  K -2 , only marginally exceeding the calculated γ = 9.34 mJ mol -1  K -2 , indicates only weak electronic correlations., (© 2022 IOP Publishing Ltd.)