title: Dielectric and electromechanical properties of rare earth calcium oxyborate piezoelectric crystals at high temperatures.
abstract: The electrical resistivity, dielectric, and electromechanical properties of ReCa(4)O(BO(3))(3) (ReCOB; Re = Er, Y, Gd, Sm, Nd, Pr, and La) piezoelectric crystals were investigated as a function of temperature up to 1000 °C. Of the studied crystals, ErCOB and YCOB were found to possess extremely high resistivity (p): p > 3 × 10(7) ω.cm at 1000 °C. The property variation in ReCOB crystals is discussed with respect to their disordered structure. The highest electromechanical coupling factor κ(26) and piezoelectric coefficient d(26) at 1000°C, were achieved in PrCOB crystals, with values being on the order of 24.7% and 13.1 pC/N, respectively. The high thermal stability of the electromechanical properties, with variation less than 25%, together with the low dielectric loss (<46%) and high mechanical quality factor (>1500) at elevated temperatures of 1000 °C, make ErCOB, YCOB, and GdCOB crystals promising for ultrahigh temperature electromechanical applications.
authors.forename: Fapeng
authors.initials: F
authors.lastname: Yu
authors.forename: Shujun
authors.initials: S
authors.lastname: Zhang
authors.forename: Xian
authors.initials: X
authors.lastname: Zhao
authors.forename: Duorong
authors.initials: D
authors.lastname: Yuan
authors.forename: Lifeng
authors.initials: L
authors.lastname: Qin
authors.forename: Qing-Ming
authors.initials: QM
authors.lastname: Wang
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Shrout
mesh_terms: D001881:Borates / Q000138:chemical synthesis / Q000737:chemistry*; D017610:Calcium Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D017097:Electric Impedance; D004563:Electrochemistry / Q000379:methods; D004581:Electronics; D006358:Hot Temperature; D008422:Materials Testing / Q000379:methods*; D019563:Mechanics; D008674:Metals, Rare Earth / Q000737:chemistry*; D014159:Transducers
chemical_list: D001881:Borates; D017610:Calcium Compounds; D008674:Metals, Rare Earth