Untitled

In this study, in order to develop the composition ceramics for low loss and low temperature sintering multilayer piezoelectric actuator, Pb(Mn 1/3 Nb 2/3 )O 3 -Pb (Ni 1/3 Nb 2/3 )O 3 -Pb(Zr 0.50 Ti 0.50 )O 3 (abbreviated as PMN-PNN-PZT) ceramics were fabricated using Li 2 CO 3 and Na 2 CO 3 as sintering aids, and their piezoelectric and dielectric characteristics were investigated according to the amount of MnO 2 addition. At the 0.2 wt% MnO 2 doped specimen sintered at 900°C, density and mechanical quality factor (Q m ) showed the maximum values of 7.81 [g/cm 3 ]and 1186, respectively. And also, at 0.1 wt% MnO 2 doped specimen, electromechanical coupling factor (k p ), piezoelectric constant (d 33 ) of specimen showed the maximum values of 0.608 and 377[pC/N], respectively. Dielectric constant (ɛ r ) slightly decreased with increasing MnO 2 . Taking into consideration the density of 7.81[g/cm 3 ], electromechanical coupling factor (k p )of 0.597 the mechanical quality factor (Q m ) of 1,186, and piezoelectric constant (d 33 ) of 356[pC/N], it could be concluded that 0.2 wt% MnO 2 doped composition ceramics sintered at 900°C was best for low loss and low temperature sintering multilayer piezoelectric actuator application.

Section: Methodssupporting

confidence: 84%

Piezoelectric properties of MnO2 doped low temperature sintering Pb(Mn1/3Nb2/3)O3–Pb(Ni1/3Nb2/3)O3–Pb(Zr0.50Ti0.50)O3 ceramics

Yoo

Lee

2008

“…The unbalance of ion valence leads to the creation of oxygen vacancies, which enhances the transfer of mass and energy between reactants, thus improving the sintering behavior and inducing an increase in grain size. However, excessive doping will drastically worsen the sintering behavior of the ceramics because a great deal MnO 2 congregate in the grain boundary [24,25]. Figure 4 shows the piezoelectric constant d 33 and the electromechanical coupling factor k p of BNBT-6 ceramics sintered at 1160°C as a function of MnO 2 addition.…”

Section: Methodsmentioning

confidence: 99%

Effects of MnO2 addition on microstructure and electrical properties of (Bi0.5Na0.5) 0.94Ba0.06TiO3 ceramics

Wang

Quanlu

2007

In this letter, MnO 2 -doped (Bi 0.5 Na 0.5 ) 0.94 Ba 0.06-TiO 3 (BNBT-6) lead-free piezoelectric ceramics were synthesized by solid state reaction, and the microstructure and electrical properties of the ceramics were investigated. X-ray diffraction (XRD) reveals that all specimens take on single perovskite type structure, and the diffraction peaks shift to a large angle as the MnO 2 addition increases. Scanning electron microscopy shows that the grain sizes increases, and then decreases with increasing the MnO 2 content. The experiment results indicate that the electrical properties of ceramics are significantly influenced by the MnO 2 content, and the ceramics with homogeneous microstructure and excellent electrical properties are obtained with addition of 0.3 wt% MnO 2 and sintered at 1160°C. The piezoelectric constant (d 33 ), the electromechanical coupling factor (k p ), the dissipation factor (tan δ) and the dielectric constant (ɛ r ) reach 160 pC/N, 0.29, 0.026 and 879, respectively. These excellent properties indicate that the MnO 2 -doped BNBT-6 ceramics can be used for actuators.

“…4, (B)-(D). This change in the crystal structure is deemed to be related to the substitution of the Mn ions for the B-site ions in the perovskite structure, as is often the case with Mn-doped PZT-based ceramics [20].…”

Section: +mentioning

confidence: 99%

Low-temperature sintering of MnO2-doped PZT–PZN Piezoelectric ceramics

Lee

Yoon

et al. 2007

The effect of MnO 2 addition on the microstructural evolution and piezoelectric properties of low temperature sinterable PZT-PZN ceramics was investigated. When a small amount of MnO 2 (≤0.5 wt% ) was added, the Mn ions were homogeneously dissolved in the PZT-PZN ceramics, leading to full densification at a temperature as low as 930°C. However, the further addition of MnO 2 hindered the densification, causing the specimen to have a high porosity and small grain size. In addition, as the MnO 2 content increased, the crystal structure of the PZT-PZN changed gradually from a tetragonal to a rhombohedral phase, due to the substitution of Mn for the B-sites in the perovskite structure. The addition of MnO 2 up to a maximum of 0.5% improved the mechanical quality factor (Q m ) of the PZT-PZN ceramics markedly, while keeping the k p and d 33 values reasonably high. The 80% PZT-20% PZN doped with 0.4 wt% MnO 2 exhibited excellent piezoelectric properties; Q m =1,000, k p =0.62, and d 33 = 330 pC/N.