Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. We study the magnetoelectric coupling in YMnO 3 single crystal, in which a part of Mn 3+ ions is substituted by nonmagnetic Ga 3+ ions. While the antiferromagnetic ordering temperature is gradually suppressed by Ga doping, the magnetocapacitance is enhanced by two orders of magnitude, which we attribute to the lifting of frustration of interlayer spin interactions in doped samples. We also find that the dielectric constant anomaly below magnetic ordering temperature is strongly anisotropic, which we explain using a phenomenological Landau description of ferroelectric antiferromagnets.

Combining long-range magnetic order with polarity in the same structure is a prerequisite for the design of (magnetoelectric) multiferroic materials. There are now several demonstrated strategies to achieve this goal, but retaining magnetic order above room temperature remains a difficult target. Iron oxides in the +3 oxidation state have high magnetic ordering temperatures due to the size of the coupled moments. Here we prepare and characterize ScFeO3 (SFO), which under pressure and in strain-stabilized thin films adopts a polar variant of the corundum structure, one of the archetypal binary oxide structures. Polar corundum ScFeO3 has a weak ferromagnetic ground state below 356 K—this is in contrast to the purely antiferromagnetic ground state adopted by the well-studied ferroelectric BiFeO3.

We have studied the magnetodielectric and magnetoelastic coupling in TbFe 3 ͑BO 3 ͒ 4 single crystals by means of capacitance, magnetostriction, and Raman spectroscopy measurements. The data reveal strong magnetic field effects on the dielectric constant and on the macroscopic sample length which are associated to long-range magnetic ordering and a field-driven metamagnetic transition. We discuss the coupling of the dielectric, structural, and magnetic order parameters and attribute the origin of the magnetodielectric coupling to phonon mode shifts according to the Lyddane-Sachs-Teller relation.

No abstract

(NBT), BaTiO 3 (BTO), and K 0.5 Bi 0.5 TiO 3 (KBT) are known but all have inferior properties to PZT. [ 2,3,5 ] Bi 3+ has a 6s 2 confi guration with crystal chemistry similar to that of Pb 2+ , and bismuthbased perovskites are attractive as they can offer high Curie and depolarization temperatures required for demanding application environments. [ 5,6 ] [ 9 ] which can be converted into a long-range polarization along this direction by the introduction of LaFeO 3 (LFO) which itself has antiferrodistortive [110] p displacements, although this orthorhombic O [110] The perovskite oxide lead zirconate titanate (PbZr 1− x Ti x O 3 ) (PZT) has extraordinary electromechanical properties at the morphotropic phase boundary (MPB), [ 1 ] making modifi ed PZT ceramics the basis for almost all actuators, sensors and related applications in use today. The MPB in the PZT solid solution occurs near x ≈ 0.48 [ 1 ] between the ferroelectric rhombohedral ( R 3 m , denoted as R [111] ) and tetragonal ( P 4 mm , denoted as T [001] ) phases, with polarizations lying along the [111] p body diagonal and [001] p edge of the primitive ≈ 4 Å ABO 3 perovskite unit cell, respectively. [1][2][3] The PZT phases are untilted and the R [111] and T [001] structures are described crystallographically, using a modifi ed Glazer notation, as a a a + , respectively, where the subscript indicates ferroelectric displacement and the superscript the nature of the octahedral tilting with respect to the primitive unit cell axes. [ 4 ] It is challenging to create an MPB in a bismuth-based lead-free system as it has proved diffi cult to prepare phases with polarization directed along the [001] p primitive cell edge in such materials. Several Pb-free MPB systems based on K 0.5 Na 0.5 NbO 3 , Na 0.5 Bi 0.5 TiO 3