Hydrothermal synthesis, structural, spectroscopic and magnetic studies of a lamellar phosphate: Ba(MnPO4)2·H2O

(Note: The full text of this document is currently only available in the PDF Version )

Jaione Escobal, José L. Mesa, José L. Pizarro, Luis Lezama, Roger Olazcuaga and Teófilo Rojo


Abstract

Ba(MnPO4)2·H2O has been prepared by hydrothermal synthesis and characterized by spectroscopic and magnetic techniques. Its crystal structure has been solved from X-ray powder diffraction data by using direct methods and refined with the Rietveld method. The compound crystallizes in the monoclinic system in the C2 space group with unit cell parameters, a = 9.457(1), b = 4.984(1), c = 8.346(1) Å and β = 92.07(1)°. The structure consists of a two-dimensional network of MnO6 octahedra, linked by phosphate anions and water molecules, which form chains along the |010| direction. The luminescence properties of Mn(II) in the compound are studied and the values of Dq and Racah parameters B and C have been calculated. The EPR spectra recorded on a polycrystalline sample at different temperatures show isotropic signals with g-values of 2.0. The intensity of the EPR signals increases with decreasing temperature down to 45 K and at lower temperatures rapidly decreases. Magnetic measurements show the presence of antiferromagnetic interactions. An analysis of the magnetic behaviour was carried out considering a theoretical model for antiferromagnetic chains with spin S = 5/2. Similar values for the J-exchange parameter inside the chains (J/k = –2.0 K) and for the J′-exchange parameter between neighbouring chains (zJ′/k = –2.0 K) are observed. These results suggest that the compound can be considered as a non-regular two-dimensional magnetic system.


References

  1. T. E. Gier and G. D. Stucky, Nature, 1991, 349, 508 CrossRef CAS.
  2. S. S. Lin and H. S. Weng, Appl. Catal. A, 1993, 105, 289 CrossRef CAS.
  3. J. Dakka and R. A. Sheldon, Netherlands Pat. 9 200 968, 1992 Search PubMed.
  4. P. Y. Feng, X. H. Bu and G. D. Stucky, J. Solid. State Chem., 1997, 129, 328 CrossRef CAS.
  5. P. Y. Feng, X. H. Bu and G. D. Stucky, J. Solid State Chem., 1997, 131, 160 CrossRef.
  6. P. Y. Feng, X. H. Bu, S. H. Tolbert and G. D. Stucky, J. Am. Chem. Soc., 1997, 119, 2497 CrossRef CAS.
  7. S. G. Carling, P. Day and D. Visser, Inorg. Chem., 1995, 34, 3917 CrossRef CAS.
  8. A. Goñi, J. L. Pizarro, L. M. Lezama, G. E. Barberis, M. I. Arriortua and T. Rojo, J. Mater. Chem., 1996, 6, 421 RSC.
  9. A. Pujana, J. L. Pizarro, L. Lezama, A. Goñi, M. I. Arriortua and T. Rojo, J. Mater. Chem., 1998, 8, 1055 RSC.
  10. I. Abrahams and K. S. Easson, Acta Crystallogr., Sect. C, 1993, 49, 925 CrossRef.
  11. J. L. Mesa, J. L. Pizarro, L. Lezama, J. Escobal, M. I. Arriortua and T. Rojo, J. Solid State Chem., 1998, 141, 508 CrossRef CAS.
  12. A. M. Buckley, S. T. Bramwell and P. Day, Z. Naturforsch., Teil B, 1998, 44, 1053.
  13. A. Goñi, L. Lezama, G. E. Barberis, J. L. Pizarro, M. I. Arriortua and T. Rojo, J. Magn. Magn. Mater., 1996, 164, 251 CrossRef CAS.
  14. S. G. Carling, P. Day and D. Visser, Solid State Commun., 1993, 88, 135 CrossRef CAS.
  15. J. L. Mesa, J. L. Pizarro, L. Lezama, A. Goñi, M. I. Arriortua and T. Rojo, Mater. Res. Bull., in press Search PubMed.
  16. M. A. G. Aranda, S. Bruque, J. P. Attfield, F. Palacios and R. B. Von Dreele, J. Solid State Chem., 1997, 132, 202 CrossRef CAS.
  17. A. Moqine, A. Boukhari and J. Darriet, J. Solid State Chem., 1993, 107, 362 CrossRef CAS and references therein.
  18. L. P. Regnault, J. Y. Henry, J. Rossat-Mignod and D. De Combariel, J. Magn. Magn. Mater., 1980, 15–18, 1021 CrossRef CAS.
  19. X. Bu, P. Feng and G. D. Stucky, J. Solid State Chem., 1997, 131, 387 CrossRef CAS.
  20. H. Effenberger, J. Solid State Chem., 1999, 142, 6 CrossRef CAS.
  21. Powder Diffraction File, Compiled by International Centre for Diffraction Data, Swarthmore, PA, 1995.
  22. J. Rodriguez-Carvajal, FULLPROF, Program Rietveld Pattern Matching Analysis of Powder Patterns, ILL Grenoble, 1994, unpublished work.
  23. A. Antomare, G. Cascarano, C. Giacovazzo, A. Guagliardi, M. C. Burla, G. Polidori and M. Camalli, J. Appl. Crystallogr., 1994, 27, 738.
  24. E. L. Muetterties and L. J. Guggenberger, J. Am. Chem. Soc., 1974, 96, 1748 CrossRef.
  25. R. Cortés, M. I. Arriortua, T. Rojo, X. Solans and D. Beltrán, Polyhedron, 1986, 5, 1987 CrossRef CAS.
  26. I. D. Brown, Structure and Bonding in Crystals, ed. M. O'Keeffe and A. Navrotsky, Academic Press, New York, 1981, vol. 2, p. 1 Search PubMed.
  27. A. Goñi, J. Rius, M. Insausti, L. Lezama, J. L. Pizarro, M. I. Arriortua and T. Rojo, Chem. Mater., 1996, 8, 1052 CrossRef CAS.
  28. L. E. Orgel, J. Chem. Phys., 1955, 23, 1004 CAS.
  29. Y. Tanabe and S. Sugano, J. Phys. Soc. Jpn., 1954, 9, 753 Search PubMed.
  30. A. B. P. Lever, Inorganic Electronic Spectroscopy, Elsevier Science Publishers B.V., Amsterdam, Netherlands, 1984 Search PubMed.
  31. K. E. Lawson, J. Chem. Phys., 1966, 44, 4159 CrossRef CAS.
  32. H. W. Wijn, L. R. Walker, J. L. Daris and H. Guggenheim, J. Solid State Commun., 1972, 11, 803 Search PubMed.
  33. P. M. Richards and M. B. Salamon, Phys. Rev. B: Condens. Matter, 1974, 9, 32 CrossRef.
  34. A. Escuer, R. Vicente, M. A. S. Goher and F. Mautner, Inorg. Chem., 1995, 34, 5707 CrossRef CAS.
  35. A. Bencini and D. Gatteschi, EPR of Exchange Coupled Systems, Springer-Verlag, Berlin–Heidelberg, 1990 Search PubMed.
  36. T. T. P. Cheung, Z. G. Soos, R. E. Dietz and F. R. Merrit, Phys. Rev. B: Condens. Matter, 1978, 17, 1266 CrossRef CAS.
  37. M. E. Fisher, Am. J. Phys., 1964, 32, 343.
  38. R. Dingle, M. E. Lines and S. L. Holt, Phys. Rev., 1969, 187, 643 CrossRef CAS.
Click here to see how this site uses Cookies. View our privacy policy here.