2017/02/28 by Kenta Shimamoto, Saumya Mukherjee, N. S. Bingham +8
Chemistry · Materials Science · Physics and Astronomy · #Chemistry #Condensed matter physics #Crystal structure #Crystallography #Dielectric #Ferroelectric and Piezoelectric Materials #Ferroelectricity #Lattice (music) #Magnetic and transport properties of perovskites and related materials #Materials science #Multiferroics #Multiferroics and related materials #Order (exchange) #Orthorhombic crystal system #Physics #Quantum mechanics #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.95.184105
published as Phys. Rev. B 95, 184105 (2017)
openalex created_date 2017/03/03 · openalex publication_date 2017/05/08 · arxiv created 2017/05/28 · arxiv updated 2017/05/30 · openalex updated_date 2026/08/06
Controlling material properties by modulating the crystalline structure has been attempted using various techniques, e.g., hydrostatic pressure, chemical pressure, and epitaxy. These techniques succeed to improve properties and achieve desired functionalities by changing the unit cell in all dimensions. In order to obtain a more detailed understanding on the relation between the crystal lattice and material properties, it is desirable to investigate the influence of a smaller number of parameters. Here, we utilize the combination of chemical pressure and epitaxy to modify a single lattice parameter of the multiferroic orthorhombic RMnO3 (R=rare\text\ensuremath-earth; o\text\ensuremath-RMnO3) system. By growing a series of o\text\ensuremath-RMnO3 (R=Gd--Lu) films coherently on (010)-oriented YAlO3 substrates, the influence of chemical pressure is reflected only along the b axis. Thus a series of o\text\ensuremath-RMnO3 with a\ensuremath∼5.18\phantom\rule0.16em0ex\AA,\phantom\rule0.16em0ex5.77\phantom\rule0.16em0ex\AA<b<5.98\phantom\rule0.16em0ex\AA, and c\ensuremath∼7.37\phantom\rule0.16em0ex\AA were obtained. Raman spectra analysis reveals that the change of the b-axis parameter induces a shift of the oxygen in the nominally ``fixed'' ca plane. Their ferroelectric ground state is independent on the b-axis parameter showing polarization of \ensuremath∼1\phantom\rule0.16em0ex\ensuremathμC\phantom\rule0.16em0excm^\ensuremath-2 along the a axis for the above-mentioned range, except for b\ensuremath∼5.94\phantom\rule0.16em0ex\AA, which corresponds to TbMnO3 showing \ensuremath∼2\phantom\rule0.16em0ex\ensuremathμC\phantom\rule0.16em0excm^\ensuremath-2. This result implies that multiferroic order of o\text\ensuremath-RMnO3 is almost robust against the b-axis parameter provided that the dimension of the ca plane is fixed to 7.37\phantom\rule0.16em0ex\AA\ifmmode×\else\texttimes\fi5.18\phantom\rule0.16em0ex\AA.