Effect of Ni doping on ferroelectric and dielectric properties of strontium barium niobate crystals

Abstract

The influence of Ni doping on the ferroelectric and dielectric properties have been examined in Sr 0.61 Ba 0.39 Nb 2 O 6 (SBN:61) relaxor crystals. The dopants introduced into SBN:61 crystals promote the switching process by reducing the value of threshold nucleation field, and thus coercive field. We present real-time studies of domain nucleation and growth processes in doped SBN:61 by the nematic liquid crystal (NLC) decoration technique. The broad phase transition and low-frequency dielectric dispersion that are exhibited by doped SBN:61 samples have a strong link to the configuration of the ferroelectrics microdomains, which in turn is strongly determined by Ni ions concentration.

Investigations on Fe-doped strontium barium niobate, single phase ferroelectric and magnetodielectric compounds

“…Further these observations are consistent with the earlier reports on Fe-, Cr-and Ni-doped SBN. 4,5 The increase in P max with increase in Fe concentration could also be associated to the increased polarization per unit cell of SBNFe systems, possibly due to the reduction in cell volume. However, the present analysis is limited to the Fe substitutions, where T m is always greater than room temperature.…”

“…Essentially, transition metal/rare earthdoped single crystal and polycrystalline SBN systems are widely investigated owing to their applications in the field of piezoelectric, pyroelectric, electro-optic, nonlinear optics, holographic recording devices, etc. [3][4][5][6][7][8] Tetragonal Strontium-Barium-Niobate (SBN) undergoes a relaxor type phase transition from a ferro to a paraelectric phase, with no strong structural changes, besides losing its center of inversion. Ferro electricity in SBN is believed to occur because of the dynamics and properties of nanodomains (polar clusters).…”

“…Further it is also observed that P-E hysteresis persists for temperatures well above its transition temperature and the substitution of transition metals like Ni causes reduction in the coercive field and improves switching properties of SBN. 4,13 Amongst the doped SBN compositions, Cr-, Mn-, Fe-, Co-, and Ni-doped SBN systems may form a special class of doped systems, owing to possible interaction between magnetic and electric order parameters. Recently a BaO-Y 2 O 3 -Fe 2 O 3 -Nb 2 O 5 TTB system is reported to exhibit both the ferroelectric and ferromagnetic hysteresis loops.…”

Ferroelectric and dielectric characterization studies on relaxor- and ferroelectric-like strontium-barium niobates

“…This is closely related to a distribution of random electric fields inherent to relaxor crystals. It is interesting to note that KWW function described the switching kinetics in SBN:61 [13] as well as the relaxing domains on the nanoscale, with PFM imaging of the domain configuration in SBN:61 doped with cerium [5].…”

“…Mostly, highresolution domain structure studies (nanoscale domains) have been performed for a congruently melting composition Sr 0.61 Ba 0.39 Nb 2 O 6 (SBN:61) by piezoresponse force microscopy (PFM) [3][4][5][6][7][8]. The microscale domain structure kinetics in SBN:61 was investigated using an electro-optic imaging microscope [9,10] and NLC method [11][12][13]. The observed specific features of the switching process were accounted for freezing or pinning domain walls connected with disordered structure of SBN crystals.…”