High-quality antiferromagnetic EuTiO3 epitaxial thin films on SrTiO3 prepared by pulsed laser deposition and postannealing

Abstract

We report on epitaxial growth and magnetic properties of EuTiO 3 thin films with a perovskite structure. Single crystalline EuTiO 3 films with atomically flat surface are grown on ͑001͒ surface of SrTiO 3 by pulsed laser deposition ͑PLD͒ and subsequent annealing in reducing atmosphere. The as-deposited films possess the crystal structure with an elongated c-axis and tend to stabilize ferromagnetically ordered Eu 2+ spins at low temperatures. Postannealing at 1000°C relaxes the out-of-plane lattice strain, and brings about a drastic change in magnetic structure; the annealed film becomes an antiferromagnet below Néel temperature of 5.1 K. The change in magnetic properties accompanied by the modification in lattice constant is discussed.

EuTiO3magnetic structure studied by neutron powder diffraction and resonant x-ray scattering

“…The two domains are related to each other by a rotation of 90 • about the c axis. Assuming an equal population for the two domains, with the magnetic moment motif abiding by 9 , describes the observed polscan data sufficiently well (χ 2 = 192). As shown in Fig.…”

“…There are only two irreducible representations (irreps) associated with the 4b site and the (0, 0, 0) propagation vector supporting antiferromagnetic ordering: mag = 6 ⊕ 9 . 6 (one-dimensional) supports antiferromagnetic ordering along the c axis while 9 (bidimensional) favors an antiferro-type order within the a,b plane. It is in general possible to distinguish the a,b plane ordering from the c axis one as neutrons are only sensitive to the magnetic moment component perpendicular to the scattering wave vector.…”

“…7,8 A material which has recently attracted attention is magnetoelectric EuTiO 3 , which show an unusual coupling between dielectric, magnetic, and structural degrees of freedom. It can also be deposited as high quality epitaxial thin films, 9 a prerequisite for envisaging practical application in functional devices. Moreover, the presence of a large polarization and ferromagnetism in strained films has been predicted theoretically and reported experimentally, although only at very low temperatures so far.…”

Magnetodielectric effect and phonon properties of compressively strained EuTiO3thin films deposited on (001)(LaAlO3)0.29Kamba1, Goian2, Орлита3 et al. 2012Phys. Rev. B220181View full textAdd to dashboardCite

“…The in-plane polarized polar modes have the Eu symmetry, whereas the out-of-plane modes have the A2u symmetry. as the bulk EuTiO 3 ) exhibit an elongated c-axis and a ferromagnetic order below 5 K, 21,22 while the same films post annealed at 1000…”

First-principles prediction of oxygen octahedral rotations in perovskite-structure EuTiO3

“…10 It has been suggested that EuTiO 3 is the prototype for studying quantum paraelectric behavior in magnetic systems. 11 In addition to these experiments on bulk EuTiO 3 , there has been a series of recent studies on EuTiO 3 thin films [12][13][14][15] motivated in part by the subsequently verified prediction that epitaxial strain should induce ferroelectricity and multiferroicity. 16,17 Likewise "chemical strain," i.e., doping at the A site with larger divalent ions, has been shown to induce ferroelectricity, e.g., in alloys with BaTiO 3 .…”