Spin-Glass Behavior and Incommensurate Modulation in High-Pressure Perovskite BiCr_0.5Ni_0.5O₃

Abstract

The BiCr(0.5)Ni(0.5)O(3) perovskite has been obtained at high pressure. Neutron and synchrotron diffraction data show a Pnma orthorhombic structure with a = 5.5947(1) Å, b = 7.7613(1) Å, and c = 5.3882(1) Å at 300 K and random B-site Cr/Ni distribution. Electron diffraction reveals an incommensurate modulation parallel to the b axis. The combination of either Cr-O-Ni (J > 0) or Cr-O-Cr/Ni-O-Ni (J < 0) nearest-neighbor spin interactions results in a random-bond spin-glass configuration. Magnetization, neutron diffraction, and muon-spin-relaxation measurements demonstrate that variations in the local bonding and charge states contribute to the magnetic frustration.

Robust Giant Tetragonal Distortion Coupled with High-Spin Co3+ in Electron-Doped BiCoO3

“…Here, the small reflections can be successfully indexed by assuming a modulation vector q inc = p a + q b with p = 0.32 and q = 0.51. Similar incommensurate structures can be found in BiCr 0.5 Ni 0.5 O 3 , Bi 1– x Ca x FeO 3 , and Bi 0.75 La 0.25 FeO 3 because of the effect of lone-pair electrons or complex charge ordering. − Our attempt to observe the ferroelectric P – E hysteresis loop was unsuccessful because of a large leakage current (Figure S2).…”

Incommensurate structures of the [CH3NH3][Co(COOH)3] compound

“…However, more complex order-disorder transitions are also possible. The competition between atomic interactions in pure inorganic ABO 3 perovskites is responsible for the occurrence of unusual instabilities, which occasionally lead to incommensurate structures (Arakcheeva et al, 2017;Khalyavin et al, 2015;Lin et al, 2015;Aré valo-Ló pez et al, 2015;Du et al, 2014;Szczecinski et al, 2014;Magdysyuk et al, 2013). The atomic interactions responsible for the incommensurate distortions involve a counter-ion displacement, as well as antiferrodistorsive motions, mainly the tilting of the oxygen octahedron centred in the B-site.…”

Anisotropic magnetic properties and giant rotating magnetocaloric effect in double-perovskite Tb2CoMnO6

“…Double perovskite compounds with appropriate combinations of several magnetic ions have been recently investigated because of their intriguing physical properties, such as metamagnetism [15][16][17], exchange bias [18,19], re-entrant spin-glass state [20][21][22][23], and multiferroicity [24][25][26][27][28], arising from the intricate magnetic interactions and ionic valence/antisite disorders between the mixed-valence magnetic ions. In double perovskite R2CoMnO6 (R = La, …, Lu) compounds, Co 2+ and Mn 4+ ions are alternately located in cornershared octahedral environments.…”