L. H. Ong, J. Osman, and D. R. Tilley, “Landau theory of second-order phase transitions in ferroelectric films,” Phys. Rev. B 63, 144109, 1–10 (2001).

E. K. Tan, J. Osman, and D. R. Tilley, “First-order phase transitions in ferroelectric films,” Solid State Commun. 116, 61–65 (2000).

Ph. Ghosez and K. M. Rabe, “Microscopic model of ferroelectricity in stress-free PbTiO_{3} ultrathin films,” Appl. Phys. Lett. 76, 2767–2769 (2000).

T. Tybell, C. H. Ahn, and J.-M. Triscone, “Ferroelectricity in thin perovskite films,” Appl. Phys. Lett. 75, 856–858 (1999).

K. H. Chew, J. Osman, R. L. Stamps, D. R. Tilley, and J. F. Webb, “Theory of far infrared spectroscopy for ferroelectric size effects,” Integr. Ferroelectr. 23, 161–186 (1999).

K. H. Chew, S. Alwi, D. R. Tilley, J. Osman, and J. F. Webb, “Optical transmission through ferroelectric thin films as a probe of surface terms,” Ferroelectrics 230, 209–214 (1999).

W. L. Zhong, Y. G. Wang, and P. L. Zhang, “Phase transitions in finite-size ferroelectrics,” Ferroelectr. Rev. 1, 131–193 (1998).

J. Osman, Y. Ishibashi, and D. R. Tilley, “Calculation of nonlinear susceptibility tensor components in ferroelectrics,” Jpn. J. Appl. Phys. 37, 4887–4893 (1998).

S. C. Lim, J. Osman, and D. R. Tilley, “The gyromagnetic Fabry–Pérot resonator. II. dipole–exchange effects,” J. Phys. Condens. Matter 10, 1891–1907 (1998).

G. L. Fischer, R. W. Boyd, R. J. Gehr, S. A. Jenekhe, J. A. Osaheni, J. E. Sipe, and L. R. Weller-Brophy, “Enhanced nonlinear optical response of composite materials,” Phys. Rev. Lett. 74, 1871–1874 (1995).

R. N. Philp and D. R. Tilley, “Exciton polaritons in thin films,” Phys. Rev. B 44, 8170–8180 (1991).

M. Lui, C. A. Ramos, A. R. King, and V. Jaccarino, “Antiferromagnetic standing-spin-wave resonance in epitaxial films of MnF_{2},” J. Appl. Phys. 67, 5518–5520 (1990).

Y. Ishibashi, “Structure and physical properties of domain walls,” Ferroelectrics 104, 299–310 (1990).

J. F. Scott, H. M. Duiker, P. D. Beale, B. Pouligny, K. Dimmler, M. Parris, D. Butler, and S. Eaton, “Properties of ceramic KNO_{3} thin-film memories,” Physica B 150, 160–167 (1988).

D. R. Tilley and B. Zeks, “Landau theory of phase transitions in thick films,” Solid State Commun. 49, 823–827 (1984).

M. G. Cottam, D. R. Tilley, and B. Zeks, “Theory of surface modes in ferroelectrics,” J. Phys. C 17, 1793–1823 (1984).

K. Abraha and D. R. Tilley, “Theory of far-infrared reflectivity and surface magnetic polaritons of rare-earth magnets,” Infrared Phys. Technol. 35, 681–699 (1994).

T. Tybell, C. H. Ahn, and J.-M. Triscone, “Ferroelectricity in thin perovskite films,” Appl. Phys. Lett. 75, 856–858 (1999).

K. H. Chew, S. Alwi, D. R. Tilley, J. Osman, and J. F. Webb, “Optical transmission through ferroelectric thin films as a probe of surface terms,” Ferroelectrics 230, 209–214 (1999).

J. F. Scott, H. M. Duiker, P. D. Beale, B. Pouligny, K. Dimmler, M. Parris, D. Butler, and S. Eaton, “Properties of ceramic KNO_{3} thin-film memories,” Physica B 150, 160–167 (1988).

G. L. Fischer, R. W. Boyd, R. J. Gehr, S. A. Jenekhe, J. A. Osaheni, J. E. Sipe, and L. R. Weller-Brophy, “Enhanced nonlinear optical response of composite materials,” Phys. Rev. Lett. 74, 1871–1874 (1995).

R. W. Boyd and J. E. Sipe, “Nonlinear optical susceptibilities of layered composite materials,” J. Opt. Soc. Am. B 11, 297–303 (1994).

J. F. Scott, H. M. Duiker, P. D. Beale, B. Pouligny, K. Dimmler, M. Parris, D. Butler, and S. Eaton, “Properties of ceramic KNO_{3} thin-film memories,” Physica B 150, 160–167 (1988).

K. H. Chew, J. Osman, R. L. Stamps, D. R. Tilley, and J. F. Webb, “Theory of far infrared spectroscopy for ferroelectric size effects,” Integr. Ferroelectr. 23, 161–186 (1999).

K. H. Chew, S. Alwi, D. R. Tilley, J. Osman, and J. F. Webb, “Optical transmission through ferroelectric thin films as a probe of surface terms,” Ferroelectrics 230, 209–214 (1999).

M. G. Cottam, D. R. Tilley, and B. Zeks, “Theory of surface modes in ferroelectrics,” J. Phys. C 17, 1793–1823 (1984).

J. F. Scott, H. M. Duiker, P. D. Beale, B. Pouligny, K. Dimmler, M. Parris, D. Butler, and S. Eaton, “Properties of ceramic KNO_{3} thin-film memories,” Physica B 150, 160–167 (1988).

J. F. Scott, H. M. Duiker, P. D. Beale, B. Pouligny, K. Dimmler, M. Parris, D. Butler, and S. Eaton, “Properties of ceramic KNO_{3} thin-film memories,” Physica B 150, 160–167 (1988).

J. F. Scott, H. M. Duiker, P. D. Beale, B. Pouligny, K. Dimmler, M. Parris, D. Butler, and S. Eaton, “Properties of ceramic KNO_{3} thin-film memories,” Physica B 150, 160–167 (1988).

G. L. Fischer, R. W. Boyd, R. J. Gehr, S. A. Jenekhe, J. A. Osaheni, J. E. Sipe, and L. R. Weller-Brophy, “Enhanced nonlinear optical response of composite materials,” Phys. Rev. Lett. 74, 1871–1874 (1995).

G. L. Fischer, R. W. Boyd, R. J. Gehr, S. A. Jenekhe, J. A. Osaheni, J. E. Sipe, and L. R. Weller-Brophy, “Enhanced nonlinear optical response of composite materials,” Phys. Rev. Lett. 74, 1871–1874 (1995).

Ph. Ghosez and K. M. Rabe, “Microscopic model of ferroelectricity in stress-free PbTiO_{3} ultrathin films,” Appl. Phys. Lett. 76, 2767–2769 (2000).

J. Osman, Y. Ishibashi, and D. R. Tilley, “Calculation of nonlinear susceptibility tensor components in ferroelectrics,” Jpn. J. Appl. Phys. 37, 4887–4893 (1998).

Y. Ishibashi, “Structure and physical properties of domain walls,” Ferroelectrics 104, 299–310 (1990).

M. Lui, C. A. Ramos, A. R. King, and V. Jaccarino, “Antiferromagnetic standing-spin-wave resonance in epitaxial films of MnF_{2},” J. Appl. Phys. 67, 5518–5520 (1990).

G. L. Fischer, R. W. Boyd, R. J. Gehr, S. A. Jenekhe, J. A. Osaheni, J. E. Sipe, and L. R. Weller-Brophy, “Enhanced nonlinear optical response of composite materials,” Phys. Rev. Lett. 74, 1871–1874 (1995).

M. Lui, C. A. Ramos, A. R. King, and V. Jaccarino, “Antiferromagnetic standing-spin-wave resonance in epitaxial films of MnF_{2},” J. Appl. Phys. 67, 5518–5520 (1990).

S. C. Lim, J. Osman, and D. R. Tilley, “The gyromagnetic Fabry–Pérot resonator. II. dipole–exchange effects,” J. Phys. Condens. Matter 10, 1891–1907 (1998).

M. Lui, C. A. Ramos, A. R. King, and V. Jaccarino, “Antiferromagnetic standing-spin-wave resonance in epitaxial films of MnF_{2},” J. Appl. Phys. 67, 5518–5520 (1990).

L. H. Ong, J. Osman, and D. R. Tilley, “Landau theory of second-order phase transitions in ferroelectric films,” Phys. Rev. B 63, 144109, 1–10 (2001).

G. L. Fischer, R. W. Boyd, R. J. Gehr, S. A. Jenekhe, J. A. Osaheni, J. E. Sipe, and L. R. Weller-Brophy, “Enhanced nonlinear optical response of composite materials,” Phys. Rev. Lett. 74, 1871–1874 (1995).

L. H. Ong, J. Osman, and D. R. Tilley, “Landau theory of second-order phase transitions in ferroelectric films,” Phys. Rev. B 63, 144109, 1–10 (2001).

E. K. Tan, J. Osman, and D. R. Tilley, “First-order phase transitions in ferroelectric films,” Solid State Commun. 116, 61–65 (2000).

K. H. Chew, S. Alwi, D. R. Tilley, J. Osman, and J. F. Webb, “Optical transmission through ferroelectric thin films as a probe of surface terms,” Ferroelectrics 230, 209–214 (1999).

K. H. Chew, J. Osman, R. L. Stamps, D. R. Tilley, and J. F. Webb, “Theory of far infrared spectroscopy for ferroelectric size effects,” Integr. Ferroelectr. 23, 161–186 (1999).

S. C. Lim, J. Osman, and D. R. Tilley, “The gyromagnetic Fabry–Pérot resonator. II. dipole–exchange effects,” J. Phys. Condens. Matter 10, 1891–1907 (1998).

J. Osman, Y. Ishibashi, and D. R. Tilley, “Calculation of nonlinear susceptibility tensor components in ferroelectrics,” Jpn. J. Appl. Phys. 37, 4887–4893 (1998).

J. F. Scott, H. M. Duiker, P. D. Beale, B. Pouligny, K. Dimmler, M. Parris, D. Butler, and S. Eaton, “Properties of ceramic KNO_{3} thin-film memories,” Physica B 150, 160–167 (1988).

R. N. Philp and D. R. Tilley, “Exciton polaritons in thin films,” Phys. Rev. B 44, 8170–8180 (1991).

J. F. Scott, H. M. Duiker, P. D. Beale, B. Pouligny, K. Dimmler, M. Parris, D. Butler, and S. Eaton, “Properties of ceramic KNO_{3} thin-film memories,” Physica B 150, 160–167 (1988).

Ph. Ghosez and K. M. Rabe, “Microscopic model of ferroelectricity in stress-free PbTiO_{3} ultrathin films,” Appl. Phys. Lett. 76, 2767–2769 (2000).

M. Lui, C. A. Ramos, A. R. King, and V. Jaccarino, “Antiferromagnetic standing-spin-wave resonance in epitaxial films of MnF_{2},” J. Appl. Phys. 67, 5518–5520 (1990).

J. F. Scott, H. M. Duiker, P. D. Beale, B. Pouligny, K. Dimmler, M. Parris, D. Butler, and S. Eaton, “Properties of ceramic KNO_{3} thin-film memories,” Physica B 150, 160–167 (1988).

G. L. Fischer, R. W. Boyd, R. J. Gehr, S. A. Jenekhe, J. A. Osaheni, J. E. Sipe, and L. R. Weller-Brophy, “Enhanced nonlinear optical response of composite materials,” Phys. Rev. Lett. 74, 1871–1874 (1995).

R. W. Boyd and J. E. Sipe, “Nonlinear optical susceptibilities of layered composite materials,” J. Opt. Soc. Am. B 11, 297–303 (1994).

K. H. Chew, J. Osman, R. L. Stamps, D. R. Tilley, and J. F. Webb, “Theory of far infrared spectroscopy for ferroelectric size effects,” Integr. Ferroelectr. 23, 161–186 (1999).

E. K. Tan, J. Osman, and D. R. Tilley, “First-order phase transitions in ferroelectric films,” Solid State Commun. 116, 61–65 (2000).

L. H. Ong, J. Osman, and D. R. Tilley, “Landau theory of second-order phase transitions in ferroelectric films,” Phys. Rev. B 63, 144109, 1–10 (2001).

E. K. Tan, J. Osman, and D. R. Tilley, “First-order phase transitions in ferroelectric films,” Solid State Commun. 116, 61–65 (2000).

K. H. Chew, S. Alwi, D. R. Tilley, J. Osman, and J. F. Webb, “Optical transmission through ferroelectric thin films as a probe of surface terms,” Ferroelectrics 230, 209–214 (1999).

K. H. Chew, J. Osman, R. L. Stamps, D. R. Tilley, and J. F. Webb, “Theory of far infrared spectroscopy for ferroelectric size effects,” Integr. Ferroelectr. 23, 161–186 (1999).

S. C. Lim, J. Osman, and D. R. Tilley, “The gyromagnetic Fabry–Pérot resonator. II. dipole–exchange effects,” J. Phys. Condens. Matter 10, 1891–1907 (1998).

J. Osman, Y. Ishibashi, and D. R. Tilley, “Calculation of nonlinear susceptibility tensor components in ferroelectrics,” Jpn. J. Appl. Phys. 37, 4887–4893 (1998).

K. Abraha and D. R. Tilley, “Theory of far-infrared reflectivity and surface magnetic polaritons of rare-earth magnets,” Infrared Phys. Technol. 35, 681–699 (1994).

R. N. Philp and D. R. Tilley, “Exciton polaritons in thin films,” Phys. Rev. B 44, 8170–8180 (1991).

M. G. Cottam, D. R. Tilley, and B. Zeks, “Theory of surface modes in ferroelectrics,” J. Phys. C 17, 1793–1823 (1984).

D. R. Tilley and B. Zeks, “Landau theory of phase transitions in thick films,” Solid State Commun. 49, 823–827 (1984).

T. Tybell, C. H. Ahn, and J.-M. Triscone, “Ferroelectricity in thin perovskite films,” Appl. Phys. Lett. 75, 856–858 (1999).

T. Tybell, C. H. Ahn, and J.-M. Triscone, “Ferroelectricity in thin perovskite films,” Appl. Phys. Lett. 75, 856–858 (1999).

W. L. Zhong, Y. G. Wang, and P. L. Zhang, “Phase transitions in finite-size ferroelectrics,” Ferroelectr. Rev. 1, 131–193 (1998).

K. H. Chew, J. Osman, R. L. Stamps, D. R. Tilley, and J. F. Webb, “Theory of far infrared spectroscopy for ferroelectric size effects,” Integr. Ferroelectr. 23, 161–186 (1999).

K. H. Chew, S. Alwi, D. R. Tilley, J. Osman, and J. F. Webb, “Optical transmission through ferroelectric thin films as a probe of surface terms,” Ferroelectrics 230, 209–214 (1999).

G. L. Fischer, R. W. Boyd, R. J. Gehr, S. A. Jenekhe, J. A. Osaheni, J. E. Sipe, and L. R. Weller-Brophy, “Enhanced nonlinear optical response of composite materials,” Phys. Rev. Lett. 74, 1871–1874 (1995).

M. G. Cottam, D. R. Tilley, and B. Zeks, “Theory of surface modes in ferroelectrics,” J. Phys. C 17, 1793–1823 (1984).

D. R. Tilley and B. Zeks, “Landau theory of phase transitions in thick films,” Solid State Commun. 49, 823–827 (1984).

W. L. Zhong, Y. G. Wang, and P. L. Zhang, “Phase transitions in finite-size ferroelectrics,” Ferroelectr. Rev. 1, 131–193 (1998).

W. L. Zhong, Y. G. Wang, and P. L. Zhang, “Phase transitions in finite-size ferroelectrics,” Ferroelectr. Rev. 1, 131–193 (1998).

Ph. Ghosez and K. M. Rabe, “Microscopic model of ferroelectricity in stress-free PbTiO_{3} ultrathin films,” Appl. Phys. Lett. 76, 2767–2769 (2000).

T. Tybell, C. H. Ahn, and J.-M. Triscone, “Ferroelectricity in thin perovskite films,” Appl. Phys. Lett. 75, 856–858 (1999).

W. L. Zhong, Y. G. Wang, and P. L. Zhang, “Phase transitions in finite-size ferroelectrics,” Ferroelectr. Rev. 1, 131–193 (1998).

K. H. Chew, S. Alwi, D. R. Tilley, J. Osman, and J. F. Webb, “Optical transmission through ferroelectric thin films as a probe of surface terms,” Ferroelectrics 230, 209–214 (1999).

Y. Ishibashi, “Structure and physical properties of domain walls,” Ferroelectrics 104, 299–310 (1990).

K. Abraha and D. R. Tilley, “Theory of far-infrared reflectivity and surface magnetic polaritons of rare-earth magnets,” Infrared Phys. Technol. 35, 681–699 (1994).

K. H. Chew, J. Osman, R. L. Stamps, D. R. Tilley, and J. F. Webb, “Theory of far infrared spectroscopy for ferroelectric size effects,” Integr. Ferroelectr. 23, 161–186 (1999).

M. Lui, C. A. Ramos, A. R. King, and V. Jaccarino, “Antiferromagnetic standing-spin-wave resonance in epitaxial films of MnF_{2},” J. Appl. Phys. 67, 5518–5520 (1990).

M. G. Cottam, D. R. Tilley, and B. Zeks, “Theory of surface modes in ferroelectrics,” J. Phys. C 17, 1793–1823 (1984).

S. C. Lim, J. Osman, and D. R. Tilley, “The gyromagnetic Fabry–Pérot resonator. II. dipole–exchange effects,” J. Phys. Condens. Matter 10, 1891–1907 (1998).

J. Osman, Y. Ishibashi, and D. R. Tilley, “Calculation of nonlinear susceptibility tensor components in ferroelectrics,” Jpn. J. Appl. Phys. 37, 4887–4893 (1998).

L. H. Ong, J. Osman, and D. R. Tilley, “Landau theory of second-order phase transitions in ferroelectric films,” Phys. Rev. B 63, 144109, 1–10 (2001).

R. N. Philp and D. R. Tilley, “Exciton polaritons in thin films,” Phys. Rev. B 44, 8170–8180 (1991).

G. L. Fischer, R. W. Boyd, R. J. Gehr, S. A. Jenekhe, J. A. Osaheni, J. E. Sipe, and L. R. Weller-Brophy, “Enhanced nonlinear optical response of composite materials,” Phys. Rev. Lett. 74, 1871–1874 (1995).

J. F. Scott, H. M. Duiker, P. D. Beale, B. Pouligny, K. Dimmler, M. Parris, D. Butler, and S. Eaton, “Properties of ceramic KNO_{3} thin-film memories,” Physica B 150, 160–167 (1988).

E. K. Tan, J. Osman, and D. R. Tilley, “First-order phase transitions in ferroelectric films,” Solid State Commun. 116, 61–65 (2000).

D. R. Tilley and B. Zeks, “Landau theory of phase transitions in thick films,” Solid State Commun. 49, 823–827 (1984).

M. G. Cottam and D. R. Tilley, Introduction to Surface and Superlattice Excitations (Cambridge University, Cambridge, UK, 1986).

S. A. Feiven and T. J. Parker, Department of Physics, University of Essex, Colchester, UK (private communication, 1994).

W. H. Press, B. P. Flannery, S. A. Teukolsky, and W. T. Vetterling, Numerical Recipes: The Art of Scientific Computing (Cambridge University, Cambridge, UK, 1989).