Dipolar ordering of molecular magnets

Physical Review B - Condensed Matter and Materials Physics

Volumn 66, Issue 6, 2002, Pages 1-7

  Fernández, Julio F ^a  

^a CSIC   (Spain)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 12244297630     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.66.064423     Document Type: Article

References (53)

1. See, for instances, D. Ruizmolina, G. Christou, and D.N. Hendrickson, Mol. Cryst. Liq. Cryst. Sci. Technol., Sect. A 343, 335 (2000).
2. R. Sessoli, D. Gatteschi, A. Caneschi, and M.A. Novak, Nature (London) 365, 141 (1993).
3. M. Novak and R. Sessoli, in Quantum Tunneling of Magnetization-QTM’94, edited by L. Gunther and B. Barbara (Kluwer, Dordrecht, Netherlands, 1955), p. 171;
4. G. Paulsen and J.G. Park, p. 189.
5. J.R. Friedman, M.P. Sarachik, J. Tejada, and R. Ziolo, Phys. Rev. Lett. 76, 3830 (1996);
6. J.M. Hernández, X.X. Zhang, F. Luis, J. Bartolomé, J. Tejada, and R. Ziolo, Europhys. Lett. 35, 301 (1996);
7. L. Thomas, F. Lionti, R. Ballou, D. Gatteschi, R. Sessoli, and B. Barbara, Nature (London) 383, 145 (1996);
8. J.M. Hernández, X.X. Zhang, F. Luis, J. Tejada, J.R. Friedman, M.P. Sarachik, and R. Ziolo, Phys. Rev. B 55, 5858 (1997);
9. S. Hill, J.A.A.J. Perenboom, N.S. Dalal, T. Hathaway, T. Stalcup, and J.S. Brooks, Phys. Rev. Lett. 80, 2453 (1998);
10. Phys. Rev. Lett.I. Chiorescu, R. Giraud, A.G.M. Jansen, A. Caneschi, and B. Barbara, 85, 4807 (2000);
11. Phys. Rev. Lett.L. Bokacheva, A.D. Kent, and M.A. Walters, 85, 4803 (2000).
12. F. Luis, J. Bartolomé, J.F. Fernández, J. Tejada, J.M. Hernández, X.X. Zhang, and R. Ziolo, Phys. Rev. B 55, 11 448 (1997).
13. F. Luis, J. Bartolomé, and J.F. Fernández, Phys. Rev. B 57, 505 (1998);
14. J.F. Fernández, F. Luis, and J. Bartolomé, Phys. Rev. Lett. 80, 5659 (1998);
15. Phys. Rev. Lett.A. Fort, A. Rettori, J. Villain, D. Gatteschi, and R. Sessoli, 80, 612 (1998);
16. J. Villain, A. Würger, A. Fort, and A. Rettori, J. Phys. (Paris) 7, 1583 (1997);
17. D.A. Garanin and E.M. Chudnovsky, Phys. Rev. B 56, 11 102 (1997).
18. M.N. Leuenberger and D. Loss, Europhys. Lett. 46, 692 (1999);
19. T. Pohjola and H. Schoeller, Phys. Rev. B 62, 15 026 (2000).
20. For a recent review, seeA. Caneschi, D. Gatteschi, C. Sangregorio, R. Sessoli, L. Sorace, A. Cornia, M.A. Novak, C. Paulsen, and W. Wernsdorfer, J. Magn. Magn. Mater. 200, 182 (1999);
21. J. Magn. Magn. Mater.B. Barbara, L. Thomas, F. Lionti, I. Chiorescu, and A. Sulpice, 200, 167 (1999).
22. C. Sangregorio, T. Ohm, C. Paulsen, R. Sessoli, and D. Gatteschi, Phys. Rev. Lett. 78, 4645 (1997).
23. W. Wernsdorfer, T. Ohm, C. Sangregorio, R. Sessoli, D. Mailly, and C. Paulsen, Phys. Rev. Lett. 82, 3903 (1999).
24. W. Wernsdorfer, R. Sessoli, and D. Gatteschi, Europhys. Lett. 47, 254 (1999).
25. W. Wernsdorfer, A. Caneschi, R. Sessoli, D. Gatteschi, A. Cornia, V. Villar, and C. Paulsen, Phys. Rev. Lett. 84, 2965 (2000).
26. W. Wernsdorfer, T. Ohm, C. Sangregorio, R. Sessoli, D. Gatteschi, and C. Paulsen, Physica B 284, 1229 (2000).
27. N.V. Prokof’ev and P.C.E. Stamp, Phys. Rev. Lett. 80, 5794 (1998);
28. N.V. Prokof’ef and P.C.E. Stamp, Rep. Prog. Phys. 63, 669 (2000).
29. N.V. Prokof’ef and P.C.E. Stamp, J. Low Temp. Phys. 113, 1147 (1998).
30. For a derivation of the tunneling rate, as well as discussions about coherent versus incoherent tunneling in MM’s, seeJ.F. Fernández, (unpublished).
31. W. Wernsdorfer and R. Sessoli, Science 284, 133 (1999).
32. J.J. Alonso and J.F. Fernández, Phys. Rev. Lett. 87, 097205 (2001).
33. How various spin crystalline systems with purely dipolar interactions order at low temperature is a subject of current interest; see, for instance, J.F. Fernández and J.J. Alonso, Phys. Rev. B 62, 53 (2000);
34. Phys. Rev. BJ.F. Fernández, J.J. Alonso65, 189901(E) (2002).
35. For ordering of (formula presented) MM’s, see alsoX. Martínez-Hidalgo, E.M. Chudnovsky, and A. Aharony, Europhys. Lett. 55, 273 (2001).
36. For ac specific-heat experiments of tunneling (formula presented) MM’s in which no collective properties play a significant role, seeF. Fominaya, J. Villain, P. Gandit, J. Chaussy, and A. Caneschi, Phys. Rev. Lett. 79, 1126 (1997);
37. Phys. Rev. Lett.for the relevant theory, seeFernández, F. Luis, and Y.J. Bartolomé, 80, 5659 (1998);
38. F. Fominaya, J. Villain, T. Fournier, P. Gandit, J. Chaussy, A. Fort, and A. Caneschi, Phys. Rev. B 59, 519 (1999).
39. F. Luis, F.L. Mettes, J. Tejada, D. Gatteschi, and L.J. de Jongh, Phys. Rev. Lett. 85, 4377 (2000);
40. F.L. Mettes, F. Luis, and L.J. de Jongh, Phys. Rev. B 64, 174411 (2001).
41. For specific-heat experiments in (formula presented) in which the role played by collective behavior is tested, see A. Morello, F.L. Mettes, F. Luis, J.F. Fernandez, J. Krzystek, G. Aromi, G. Christou, and L.J. de Jongh (unpublished).
42. N. Aliaga, K. Folting, D.N. Hendrickson, and G. Christou, Polyhedron 20, 1273 (2001), and references therein.
43. T. Ohm, C. Sangregorio, and C. Paulsen, Eur. Phys. J. B 6, 195 (1998); see also Ref. 14.
44. A. Cuccoli, A. Rettori, E. Adam, and J. Villain, Eur. Phys. J. B 12, 39 (1999).
45. E.M. Chudnovsky, Phys. Rev. Lett. 84, 5676 (2000);
46. Phys. Rev. Lett.N.V. Prokof’ev and P.C.E. Stamp, 84, 5677 (2000);
47. Phys. Rev. Lett.W. Wernsdorfer, C. Paulsen, and R. Sessoli, 84, 5678 (2000).
48. Actually, (formula presented) and q depend somewhat on temperature. For more details about their behavior, see Sec. IV.
49. A specific heat that peaks at (formula presented) has recently been observed experimentally in (formula presented) (Ref. 23).
50. A distribution of tunneling energy windows is not considered here. Such distributions occur in some alternative theories of magnetic tunneling at very low temperature, such as inE.M. Chudnovsky and D.A. Garanin, Phys. Rev. Lett. 87, 187203 (2001);
51. D.A. Garanin and E.M. Chudnovsky, Phys. Rev. B 65, 094423 (2002).
52. For the effect local magnetic field variations that take place while tunneling occurs have on Landau-Zener-type experiments, see, J. Liu, B. Wu, L.B. Fu, R.B. Diener, and Qian Niu, Phys. Rev. B 65, 224401 (2002).
53. The value of (formula presented) is easily checked numerically. Also, (formula presented), where (formula presented) is Riemann’s zeta function, M. Abramovitz and I. Stegun, Handbook of Mathematical Functions (National Bureau of Standards Applied Mathematics Series, Washington, D. C., 1964), p. 807.