Magnetic phases in UNi2Si2

• Authors: Pavel Svoboda , Pavel Javorský , Fuminori Honda , Vladimír Sechovský , Alois Menovsky
• Languages of publication: EN

Abstracts

EN

The tetragonal compound UNi2Si2 exhibits in zero magnetic field three different antiferromagnetic phases belowT
N=124 K. They are formed by ferromagnetic basal planes, which are antiferromagnetically coupled along thec-axis with the propagation vectorq=(0, 0, q
z). Two additional order-order magnetic phase transitions are observed below T
N, namely atT
1=108 K and T
2=40 K in zero magnetic field. All three phases exhibit strong uniaxial anisotropy confining the U moments to a direction parallel to the c-axis. UNi2Si2 single crystals were studied in detail by measuring bulk thermodynamic properties, such as thermal expansion, resistivity, susceptibility, and specific heat. A microscopic study using neutron diffraction was performed in magnetic fields up to 14.5 T parallel to the c-axis, and a complex magnetic phase diagram has been determined. Here, we present the analysis of specific-heat data measured in magnetic fields up to 14 T compared with the results of the neutron-diffraction study and with other thermodynamic properties of UNi2Si2.

Keywords

EN

Specific heat; Uranium intermetallic compound; Antiferromagnetism; Magnetocaloric effect; 75.50.-y; 65.40.+g; 75.30.-m

• Publisher: De Gruyter Open
• Journal: Open Physics
• Year: 2004
• Volume: 2
• Issue: 2
• Pages: 397-418

Dates

published

1 - 6 - 2004

online

1 - 6 - 2004

Contributors

author

Pavel Svoboda

• Department of Electronic Structures, Charles University, Ke Karlovu 5, 121 16, Prague 2, The Czech Republic

author

Pavel Javorský

• Department of Electronic Structures, Charles University, Ke Karlovu 5, 121 16, Prague 2, The Czech Republic

author

Fuminori Honda

• Department of Electronic Structures, Charles University, Ke Karlovu 5, 121 16, Prague 2, The Czech Republic

author

Vladimír Sechovský

• Department of Electronic Structures, Charles University, Ke Karlovu 5, 121 16, Prague 2, The Czech Republic

author

Alois Menovsky

• Van der Waals-Zeeman Institute, University of Amsterdam, Valckenierstraat 65, 1018 XE, Amsterdam, The Netherlands

References

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• [2] H. Lin, L. Rebelsky, M.F. Collins, J.D. Garrett and W.J.L. Buyers: “Magnetic Structure of UNi2Si2”, Phys. Rev. B, Vol. 43, (1991), pp. 13232–13239. http://dx.doi.org/10.1103/PhysRevB.43.13232[Crossref]
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• [4] P. Svoboda, P. Javorský, V. Sechovský, A.A. Menovsky, M. Hofmann and N. Stuesser: “Magnetic phase diagram and critical scattering of UNi2Si2”, Physica B, Vol. 322, (2002), pp. 248–251. http://dx.doi.org/10.1016/S0921-4526(02)01189-4[Crossref]
• [5] P. Svoboda, P. Javorský, V. Sechovský, and A.A. Menovsky: “Magnetic phase diagram of UNi2Si2 in high fields”, Physica B, Vol. 276–278, (2000), pp. 686–687. http://dx.doi.org/10.1016/S0921-4526(99)01709-3[Crossref]
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• [7] P. Svoboda, P. Javorský, M. Diviš, V. Sechovský, F. Honda, G. Oomi and A.A. Menovsky: “Importance of anharmonic terms in the analysis of the specific heat of UNi2Si2-art. no. 212408”, Phys. Rev. B, Vol. 63, (2001), pp. 212408-1–212408-4. http://dx.doi.org/10.1103/PhysRevB.63.212408[Crossref]

Identifiers

DOI

10.2478/BF02475639