TY - JOUR
T1 - Comprehensive study on ferroelectricity induced by a proper-screw-type magnetic ordering in multiferroic CuFeO2
T2 - Nonmagnetic impurity effect on magnetic and ferroelectric order
AU - Nakajima, T.
AU - Mitsuda, S.
AU - Takahashi, K.
AU - Yamano, M.
AU - Masuda, K.
AU - Yamazaki, H.
AU - Prokes, K.
AU - Kiefer, K.
AU - Gerischer, S.
AU - Terada, N.
AU - Kitazawa, H.
AU - Matsuda, M.
AU - Kakurai, K.
AU - Kimura, H.
AU - Noda, Y.
AU - Soda, M.
AU - Matsuura, M.
AU - Hirota, K.
PY - 2009/6/16
Y1 - 2009/6/16
N2 - We refined the magnetic structure of a ferroelectric (FE) phase of multiferroic CuFe1-x Gax O2 with x=0.035 by complementary use of spherical neutron polarimetry and a four-circle neutron-diffraction measurement, revealing that the proper-screw-type magnetic structure in the ferroelectric phase has a finite ellipticity of ∼0.9. By means of polarized neutron-diffraction and in-situ pyroelectric measurements, we also investigated the quantitative relationship between the macroscopic ferroelectric polarization (P) and the asymmetry in volume fractions with left-handed and right-handed helical magnetic order in CuFe1-x Alx O2 with x=0.0155 and CuFe1-x Gax O2 with x=0.035. These measurements revealed that the substitution of a small amount of nonmagnetic Ga3+ or Al3+ ions does not significantly change the magnitude of the local ferroelectric polarization but does reduce the sensitivity of P to the poling electric field (Ep). This implies that the mobility of the magnetic domain walls, which is sensitive to magnetic defects due to nonmagnetic substitution, determines the sensitivity of P to Ep because of a one-to-one correspondence between the magnetic and ferroelectric domains.
AB - We refined the magnetic structure of a ferroelectric (FE) phase of multiferroic CuFe1-x Gax O2 with x=0.035 by complementary use of spherical neutron polarimetry and a four-circle neutron-diffraction measurement, revealing that the proper-screw-type magnetic structure in the ferroelectric phase has a finite ellipticity of ∼0.9. By means of polarized neutron-diffraction and in-situ pyroelectric measurements, we also investigated the quantitative relationship between the macroscopic ferroelectric polarization (P) and the asymmetry in volume fractions with left-handed and right-handed helical magnetic order in CuFe1-x Alx O2 with x=0.0155 and CuFe1-x Gax O2 with x=0.035. These measurements revealed that the substitution of a small amount of nonmagnetic Ga3+ or Al3+ ions does not significantly change the magnitude of the local ferroelectric polarization but does reduce the sensitivity of P to the poling electric field (Ep). This implies that the mobility of the magnetic domain walls, which is sensitive to magnetic defects due to nonmagnetic substitution, determines the sensitivity of P to Ep because of a one-to-one correspondence between the magnetic and ferroelectric domains.
UR - https://www.scopus.com/pages/publications/67650046408
U2 - 10.1103/PhysRevB.79.214423
DO - 10.1103/PhysRevB.79.214423
M3 - Article
AN - SCOPUS:67650046408
SN - 1098-0121
VL - 79
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 21
M1 - 214423
ER -