We have investigated magnetic field dependences of a ferroelectric incommensurate-helimagnetic order in a trigonal magneto-electric (ME) multiferroic CuFe1−xAlxO2 with x = 0.015, which exhibits the ferroelectric phase as a ground state, by means of neutron diffraction, magnetization and dielectric polarization measurements under magnetic fields applied along various directions. From the present results, we have established the H-T magnetic phase diagrams for the three principal directions of magnetic fields; (i) parallel to the c axis, (ii) parallel to the helical axis, and (iii) perpendicular to the c and the helical axes. While the previous dielectric polarization (P ) measurements on CuFe1−xGaxO2 with x = 0.035 have demonstrated that the magnetic field dependence of the 'magnetic domain structure' results in distinct magnetic field responses of P [S. Seki et al., Phys. Rev. Lett., 103 237601 (2009)], the present study have revealed that the anisotropic magnetic field dependence of the ferroelectric helimagnetic order 'in each magnetic domain' can be also a source of a variety of magnetic field responses of P in CuFe1−xAxO2 systems (A =Al, Ga).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.