VTechWorks staff will be away for the Thanksgiving holiday beginning at noon on Wednesday, November 27, through Friday, November 29. We will resume normal operations on Monday, December 2. Thank you for your patience.

Scholarly Works, Center for Intelligent Material Systems and Structures (CIMSS)

Permanent URI for this collection

https://hdl.handle.net/10919/24824

Browse

Browsing Scholarly Works, Center for Intelligent Material Systems and Structures (CIMSS) by Author "Cho, Kyung-Hoon"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Direct and converse effect in magnetoelectric laminate composites
    Cho, Kyung-Hoon; Priya, Shashank (AIP Publishing, 2011-06-01)
    In this letter, we analyze the direct and converse effect in laminate composites of magnetostrictive and piezoelectric materials. Our results deterministically show that direct magnetoelectric (ME) effect is maximized at antiresonance frequency while the converse ME effect is maximized at resonance frequency of the laminate composite. We explain this phenomenon by using piezoelectric constitutive equations and combining it with resonance boundary conditions. The dominant factor controlling the position of peak ME coefficient was found to be frequency dependent capacitance of piezoelectric layer. This study will provide guidance toward the development of magnetic field sensors based on direct effect and communication components based on converse effect. (C) 2011 American Institute of Physics. [doi:10.1063/1.3584863]
  • Thumbnail Image
    Giant energy density in 001 -textured Pb(Mg1/3Nb2/3)O-3-PbZrO3-PbTiO3 piezoelectric ceramics
    Yan, Yongke; Cho, Kyung-Hoon; Maurya, Deepam; Kumar, Amit; Kalinin, Sergei; Khachaturyan, Armen G.; Priya, Shashank (AIP Publishing, 2013-01-01)
    Pb(Zr,Ti)O-3 (PZT) based compositions have been challenging to texture or grow in a single crystal form due to the incongruent melting point of ZrO2. Here we demonstrate the method for achieving 90% textured PZT-based ceramics and further show that it can provide highest known energy density in piezoelectric materials through enhancement of piezoelectric charge and voltage coefficients (d and g). Our method provides more than similar to 5x increase in the ratio d(textured)/d(random). A giant magnitude of d.g coefficient with value of 59 000 x 10(-15) m(2) N-1 (comparable to that of the single crystal counterpart and 359% higher than that of the best commercial compositions) was obtained. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4789854]
  • Thumbnail Image
    Phase transition and temperature stability of piezoelectric properties in Mn-modified Pb(Mg1/3Nb2/3)O-3-PbZrO3-PbTiO3 ceramics
    Yan, Yongke; Kumar, Amit; Correa, Margarita; Cho, Kyung-Hoon; Katiyar, Ram S.; Priya, Shashank (AIP Publishing, 2012-04-01)
    This study investigates the effect of two different Mn modifiers [MnO2 and Pb(Mn1/3Nb2/3)O-3(PMnN)] on the of phase transitions in Pb(Mg1/3Nb2/3)O-3-PbZrO3-PbTiO3 ceramics. The temperature dependence of polarization derived from measured pyroelectric current indicated change in nature of phase transition with MnO2 doping. This phenomenon was supported by the temperature evolution of the linear softening of low lying hard lattice mode as revealed by Raman analysis. The grain size was found to increase with MnO2 doping (5X) while decrease with PMnN modification (0.5X). Interestingly, the piezoelectric constant of MnO2 modified composition showed negligible degradation (<1%) even after heat treatment very close to the ferroelectric-paraelectric transition temperature. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3703124]
  • Thumbnail Image
    Piezoelectric properties and temperature stability of Mn-doped Pb(Mg1/3Nb2/3)-PbZrO3-PbTiO3 textured ceramics
    Yan, Yongke; Cho, Kyung-Hoon; Priya, Shashank (AIP Publishing, 2012-03-01)
    In this letter, we report the electromechanical properties of textured 0.4Pb(Mg1/3Nb2/3) O-3-0.25PbZrO(3)-0.35PbTiO(3) (PMN-PZT) composition which has relatively high rhombohedral to tetragonal (R-T) transition temperature (TR-T of 160 degrees C) and Curie temperature (T-C of 234 degrees C) and explore the effect of Mn-doping on this composition. It was found that MnO2-doped textured PMN-PZT ceramics with 5 vol.% BaTiO3 template (T-5BT) exhibited inferior temperature stability. The coupling factor (k(31)) of T-5BT ceramic started to degrade from 75 degrees C while the random counterpart showed a very stable tendency up to 180 degrees C. This degradation was associated with the "interface region" formed in the vicinity of BT template. MnO2 doped PMN-PZT ceramics textured with 3 vol.% BT and subsequently poled at 140 degrees C (T-3BT140) exhibited very stable and high k(31) (>0.53) in a wide temperature range from room temperature to 130 degrees C through reduction in the interface region volume. Further, the T-3BT140 ceramic exhibited excellent hard and soft combinatory piezoelectric properties of d(33) = 720 pC/N, k(31) = 0.53, Q(m) = 403, delta = 0.3% which are very promising for high power and magnetoelectric applications. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3698157]