Zdenek Arnold

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In Ni-Mn-Ga ferromagnetic shape memory alloys, Co-doping plays a major role in determining a peculiar phase diagram where, besides a change in the critical temperatures, a change of number, order and nature of phase transitions (e.g., from ferromagnetic to paramagnetic or from paramagnetic to ferromagnetic, on heating) can be obtained, together with a(More)
Effects of temperature and pressure on magnetic, elastic, structural, and thermal properties of Tb5Si2Ge2 have been studied by means of macroscopic (thermal expansion and magnetization) and microscopic (neutron powder diffraction) techniques. We present evidence that the high-temperature second-order ferromagnetic transition can be coupled with the(More)
Magnetic and structural properties of single crystalline Gd5Si2Ge2 under hydrostatic pressure have been characterized by using magnetization, linear thermal expansion, and compressibility measurements. A strong dependence of Curie temperature on pressure, dTC∕dP=+4.8 K∕kbar, is observed in contrast with the smaller values of about 3 K∕kbar found in(More)
The pressure dependence of the saturation magnetization and Curie temperature was studied in melt-spun Fe60Mn20B20, Fe56Mn24B20 and Fe75B25 amorphous alloys up to 0.9 GPa, corresponding to volume changes up to 0.45%. In addition, in situ high-pressure (up to 40 GPa) x-ray diffraction was performed to determine the compressibility of the latter two alloys.(More)
The magnetic properties of layered hydroxylammonium fluorocobaltate (NH(3)OH)(2)CoF(4) were investigated by measuring its dc magnetic susceptibility in zero-field-cooled (ZFC) and field-cooled (FC) regimes, its frequency dependent ac susceptibility, its isothermal magnetization curves after ZFC and FC regimes, and its heat capacity. Effects of pressure and(More)
We present the results of magnetization and AC susceptibility measurements performed on ferrimagnetic Mn(3)(2+)[Cr(III)(CN)(6)](2)·12H(2)O and ferromagnetic Ni(3)(2+)[Cr(III)(CN)(6)](2)·12H(2)O systems under pressures up to 0.9 GPa in a commercial SQUID magnetometer. The magnetization process is affected by pressure: magnetization saturates at higher(More)
Pressure effects on the stability of magnetic phases in La(1.4)Sr(1.6)Mn(2)O(7) have been studied using magnetization measurements and neutron diffraction. At ambient conditions this material is a quasi-two-dimensional ferromagnet. On cooling it becomes ordered three dimensionally: at 90 K La(1.4)Sr(1.6)Mn(2)O(7) it becomes an antiferromagnet, and at 65 K(More)
Magnetization and ultrasound measurements have been performed in pulsed magnetic fields up to 60 T on a ferrimagnetic HoFe5Al7 single crystal (Curie temperature TC = 216 K, compensation point Tcomp = 65 K) with a tetragonal crystal structure of the ThMn12-type. The compound exhibits a high magnetic anisotropy of the easy-plane type. A large anisotropy is(More)
The giant magnetocaloric compound Gd5Ge4 is the only member of the Gd5(SixGe1-x)4 family where three-dimensional exchange interactions between two-dimensional correlated layers of the crystallographic structure are so weak that spontaneous ferromagnetism does not set in at any temperature. In this Letter we explore the possibility to reach the ferromagnetic(More)
A system for direct measurements of the magneto-caloric effect (MCE) exploits a rapid transport of a sample into or from magnetic field in permanent Halbach-type (1 T) or superconducting (4.7 T) magnets. Time dependence of induced changes of the sample temperature, ΔT(t), is detected directly by the differential Cu-Constantan-Cu micro-thermocouples with(More)