arXiv subjects

Ragini

Publications and source records attributed to Ragini.

2 recordsLinked to original sources

arXiv2008

Origin of high piezoelectric response of Pb(Zr_xTi_1-x)O_3 at the morphotropic phase boundary: Role of elastic instability

Temperature dependent structural changes in a nearly pure monoclinic phase composition (x=0.525) of Pb(Zr_xTi_1-x)O_3 (PZT) have been investigated using Rietveld analysis of high-resolution synchrotron powder x-ray diffraction data and correlated with changes in the dielectric constant and planar electromechanical coupling coefficient. Our results show that the intrinsic piezoelectric response of the tetragonal phase of PZT is higher than that of the monoclinic phase. It is also shown that the high piezoelectric response of PZT may be linked with an anomalous softening of the elastic modulus (1/S_11) of the tetragonal compositions closest to the morphotropic phase boundary.

cond-mat.mtrl-sci↗

arXiv2004

A Comparison of the Cc and R3c Space Groups for the Superlattice Phase of Pb(Zr0.52Ti0.48)O3

Recent controversy about the space group of the low temperature superlattice phase of Pb(Zr0.52Ti0.48)O3 is settled. It is shown that the R3c space group for the superlattice phase cannot correctly account for the peak positions of the superlattice reflections present in the neutron diffraction patterns. The correct space group is reconfirmed to be Cc. A comparison of the atomic coordinates of Cc and Cm space groups is also presented to show that in the absence of superlattice reflections, as is the case with XRD data, one would land up in the Cm space group. This superlattice phase is found to coexist with another monoclinic phase of Cm space group.

cond-mat.mtrl-sci↗