Magnetic ordering induced ferroelectricity in α-Cu2V2O7 studied through non-magnetic Zn doping

Abstract

We have studied the magnetic and electronic properties of Cu2-xZnxV2O7 by magnetization, specific heat, and dielectric measurements. X-ray structural analysis shows a Zn-mediated phase transition from the α- to the β-phase beyond a critical Zn concentration of xc = 0.15. While Cu2V2O7 exhibits a canted antiferromagnetism with an associated weak ferromagnetism in the α-phase, the β-phase is purely antiferromagnetic. The spin canting arises due to the Dzyaloshinskii-Moriya exchange interaction in the anti-symmetric α-phase. The temperature dependence of the heat capacity for the sample in the α-phase shows a clear lambda like transition at a temperature where the magnetic susceptibility also displays an anomaly and indicates an onset of long range magnetic ordering. Dielectric properties display a clear anomaly around the magnetic transition temperature in α-Cu2V2O7. The anomaly weakens with the increase in the Zn concentration and disappears at the doping level where α to β phase transition occurs. This confirms the existence of magneto-electric coupling in α-Cu2V2O7 but not in its β-phase. Analysis of the experimental data shows that magneto-electric coupling is non-linear in nature, which is in agreement with the Landau theory of continuous phase transition. So, α-Cu2V2O7 establishes itself as a promising candidate for magnetic multiferroics.

Spin Seebeck effect in the polar antiferromagnet α−Cu2V2O7

“…However, in the low-H regime below 3 T, a weak ferromagnetic moment with a hysteresis loop was observed in the magnetization curve. The weak ferromagnetic moment whose magnitude is almost 0.01 µ B /Cu 2+ at H ≈ 0 is ascribed to small field-induced canting due to the DM interaction [6][7][8][9][10]20]. When H increases up to 6.5 T, M abruptly increases from 0.07 to 0.11 µ B /Cu 2+ .…”

Cobalt-doped copper vanadate: a dual active electrocatalyst propelling efficient H2 evolution and glycerol oxidation in alkaline water

“…26 Cu2V2O7 has also been substantially investigated as photo-anode material, while the transition metal doped counterparts such as Co-Mg doped, Zn doped Cu2V2O7 have demonstrated multiferroic and dielectric properties. 27,28 Cu2V2O7 was also doped with divalent 3d-transition metals Zn (II) and Mn(II) to further explore their prospective applications in photocatalysis.…”

“…26 Cu 2 V 2 O 7 has also been substantially investigated as a photo-anode material, while its transition metal doped counterparts such as Co-Mg doped and Zn doped Cu 2 V 2 O 7 have demonstrated multiferroic and dielectric properties. 27,28 Cu 2 V 2 O 7 was also doped with the divalent 3d-transition metals Zn(II) and Mn(II) to further explore their prospective applications in photocatalysis. Despite the commendable progress in this realm, the specic inuence of doped copper vanadates is mostly restricted to photoanode, supercapacitor, battery, and photocatalyst-based applications.…”

Photoelectrochemical properties of copper pyrovanadate (Cu2V2O7) thin films synthesized by pulsed laser deposition

“…Their study shows an optimal crystallite size at 40 nm corresponding to the hole diffusion length, estimated between 20 and 40 nm. 18 Copper pyrovanadates (a-or b-Cu 2 V 2 O 7 oxides) have also been studied for other applications, in particular for: (i) magnetoelastic and ferromagnetic coupling properties; (ii) ferroelectric properties induced by a magnetic order; 19 (iii) photodegradation properties of azo-dye in water; 20,21 (iv) solar water splitting; 22,23 (v) catalytic SO 3 decomposition; 24 (vi) cathode materials in high voltage Li-batteries. [25][26][27] Copper pyrovanadate oxides have three polymorphic phases: 30 Under normal pressure and temperature conditions, aor b-Cu 2 V 2 O 7 phase can be synthesized.…”