Observation of strong magnetoelectric coupling and ferromagnetism at room temperature in Fe substituted ferroelectric BaZr0.05Ti0.95O3 thin films

Abstract

Single phase polycrystalline thin films (∼100 nm) of BaZr0.05(FexTi1−3x/4)0.95O3, with x = 0 (BZT) and 0.015 (BZFT15), were grown on Pt/TiO2/SiO2/Si substrate using pulsed laser deposition technique. Room temperature ferromagnetism with a remanent magnetization (Mr) ∼ 1.1 × 10−1 emu/cm3 and a coercive field (Hc) ∼ 0.1 kOe was observed in BZFT15 film. The ferroelectric domain switching in both BZT and BZFT15 films is confirmed by piezoresponse force microscopy (PFM). The magnetoelectric coupling coefficient (α) measured at room temperature in the BZFT15 film in in-plane magnetized-out of plane polarized configuration (L-T mode) was found to be ∼165 mV/cm Oe. It is argued that the observed ferromagnetism in BZFT15 films arises from the oxygen vacancy (Ov) mediated (Fe3+–Ov–Fe3+) exchange.

Magnetoelectrics: Three Centuries of Research Heading Towards the 4.0 Industrial Revolution

“…This work demonstrated a maximum ME coefficient of 2 mV•cm −1 •Oe −1 at a temperature of 120 K [27]. Reproduced with permission from [25]. c) ME coefficient for a HAC =3 Oe at 993 Hz [26].…”

“…The ME coefficient of the samples with 1% Mn and 3% Mn is almost constant due to low amount of Mn, but in the 5% Mn one, a variation is observed for magnetic fields larger than 2000 Oe, leading to ME coefficient of 3.36584 mV·cm −1 ·Oe −1 at 2696 Oe, higher than the one for 1% Mn (≈ 0.170 mV·cm −1 ·Oe −1 at 2993 Oe) and 3% Mn (0.67 mV·cm −1 ·Oe −1 at 2792 Oe) samples [ 24 ]. Kumari et al [ 25 ] developed a polycrystalline thin film by PLD of BaZr 0.05 (FexTi 1−3x/4 ) 0.95 O 3 grown on Pt/TiO 2 /SiO 2 /Si substrate ( Figure 6 a)). The ME coefficient at room temperature was ≈165 mV· cm −1 ·Oe −1 at 900 Oe for the x = 0.015 sample, Figure 6 b) [ 25 ].…”

“…Kumari et al [ 25 ] developed a polycrystalline thin film by PLD of BaZr 0.05 (FexTi 1−3x/4 ) 0.95 O 3 grown on Pt/TiO 2 /SiO 2 /Si substrate ( Figure 6 a)). The ME coefficient at room temperature was ≈165 mV· cm −1 ·Oe −1 at 900 Oe for the x = 0.015 sample, Figure 6 b) [ 25 ]. Joginder et al [ 26 ] synthesized polycrystalline single phase Bi 4−x Sm x Ti 3−x Fe x O 12±δ (0 ≤ x ≤ 0.3) ceramics with a room temperature ME coefficient of 0.84 mV·cm −1 ·Oe −1 for x = 0.3 at 993 Hz with an applied AC field of 3 Oe, Figure 6 c).…”

“… ( a ) The schematic representation of the experimental conditions; and ( b ) M–E coupling coefficient versus applied magnetic field measured in both in-plane magnetized-out of plane polarized configuration (L–T) and out of plane magnetized-out of plane polarized (T–T) modes. Reproduced with permission from [ 25 ]. ( c ) ME coefficient for a H AC = 3 Oe at 993 Hz [ 26 ].…”

Magnetoelectric effect in doped magnetic ferroelectrics

“…Transition metal (TM)-doped BaTiO 3 (BTO) is the most studied material in this family. While both order parameters are simultaneously non-zero in DMFE, the coupling between them (magneto-electric effect) is very weak and not enough studied [16][17][18]. Mostly the magneto-electric (ME) effect in DMFE is related to spin-orbit interaction leading to influence of electric polarization on the material magnetic properties.…”