Lattice Distortion Coupled with Magnetic Ordering in a Triangular Lattice Antiferromagnet CuCrO₂

Magnetic structure of CuCrO2: a single crystal neutron diffraction study

“…evidence for in-plane distortions have been observed in high resolution X-ray diffraction measurements [5]. This is in agreement with small structural distortion observed in the related CuFeO 2 system [9].…”

“…The commensurate case would correspond to the classic 120 • magnetic ground state of the 2-dimensional triangular lattice. The cause of the incommensurability of the propagation vector has been discussed earlier, and two different explanations have been proposed: either an inplane lattice distortion [4,5] or interlayer exchange interaction [20][21][22][23]. The latter is in better agreement with the occurrence of 3-dimensional order, although it had been shown that an interlayer exchange has to be relatively small (<0.2meV) [24].…”

Lattice dynamics and thermal transport in multiferroicCuCrO2

“…Thus, it presents an opportunity to study the direct coupling between the magnetic and ferroelectric order parameters [3,4]. A number of studies have investigated the crystal structure, magnetic excitations, magnetization, and electric polarization in CuCrO 2 [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], but little is known about the phonons and their coupling or response to the magnetic/ferroelectric ordering.…”

“…Although the polarization is thought to arise from proper-screw type magnetic order [21], there is evidence of in-plane structural symmetry breaking across the magnetic transition in several delafossite compounds [7,22]. This structural distortion arises from magnetoelastic coupling, which is observed in a wide range of hexagonal manganites and delafossites [2,7,[22][23][24]. The structural distortion across T N could possibly change the bonding environment and thus the exchange constants as well as interatomic force constants, thus altering both the spin and phonon dynamics.…”

The Structural and Magnetic Properties of CuRh1−x Mn x O2 (0 ≤ x ≤ 0.1) Delafossite Oxide

“…ABO 2 -type materials, which have two-dimensional (2D) layered structures consisting of triangular lattices made up of magnetic B-site trivalent cations, have been studied as typical frustrated triangular-lattice spin systems [3]. In particular, CuFeO 2 and CuCrO 2 have been extensively studied in terms of magnetoelastic coupling and magnetoelectric multiferroics, which are considered to be associated with, spin frustration [4][5][6][7]. In other hands, geometrically frustrated magnetic systems have received a great deal of attention because their ordered or unordered ground states are often very exotic [1][2][3].…”