Design and Directional Growth of (Mg_1−xZn_x)(Al_1−yCr_y)₂O₄ Single‐Crystal Fibers for High‐Sensitivity and High‐Temperature Sensing Based on Lattice Doping Engineering and Acoustic Anisotropy

Abstract

High-performance temperature sensors for the harsh environment are vital components for meeting the increasing demands for the development of existing and emerging technologies. In this study, specifically oriented (Mg 1−x Zn x )(Al 1−y Cr y ) 2 O 4 single-crystal fibers (SCF) are grown by the laserheated pedestal growth technique and used as acoustic waveguides for ultrasonic temperature sensors (UTS) for the first time. The anisotropic sensor performance of the MgAl 2 O 4 SCF-UTS are investigated under a longitudinal wave and transverse wave conditions, and the [110]-oriented MgAl 2 O 4 SCF-UTS is found to have the highest sensitivity and resolution among all the MgAl 2 O 4 SCF-UTS. On this basis, a unit sensitivity of 40.38-67.50 ns °C−1 m −1 and a resolution of 1.24-0.74 °C are achieved for the [110]-oriented (Mg 0.9 Zn 0.1 )(Al 0.995 Cr 0.005 ) 2 O 4 SCF-UTS in the range of 20-1200 °C, both of which represent the best sensor performance achieved by a SCF-UTS to date. The positive temperature-dependent sensor performance, accompanied by a high working temperature (≈2000 °C) and outstanding anti-oxidation, indicates that the [110]-oriented (Mg 0.9 Zn 0.1 )(Al 0.995 Cr 0.005 ) 2 O 4 SCF-UTS is a promising candidate for ultrahigh temperature sensors. This study demonstrates a feasible strategy for the rational design of high-performance temperature sensors through a combination of crystal design, acoustic anisotropy, and lattice doping engineering.

A Couple-Free Structured LuAG:Ce-LuAG Scintillating Single Crystal Fiber Grown by a Laser-Heated Pedestal Growth Method

“…The Laue back-reflection patterns were collected from various positions along the growth direction of LuAG:Ce-LuAG SSCF, as shown in Figure e. The Laue back-reflection measurements have been widely used to precisely investigate the crystallinity and uniformity of as-grown crystals. , As shown in Figure d, the characteristic Laue back-reflection patterns along the growth direction of LuAG:Ce-LuAG SSCF at various positions (1–6) are uniform, clear, bright, and consistent. This observation indicates that the high crystallinity of LuAG:Ce-LuAG SSCF is well maintained along the growth direction of the whole fiber.…”

The Growth and Spectroscopic Properties of Er, Nd: YSGG Single Crystal Fibers

“…The laser-heated pedestal growth method (LHPG) utilizes a focused CO 2 laser beam to heat the source rods to form a melting zone; the fast crystal growth can be achieved when the oriented seed crystal touches the hemispherical melting zone. It can be used to obtain extremely high-melting materials and ultra fine crystal fibers [13,14].…”

Broadband BiOCl Nonlinear Saturable Absorber for Watt‐Level Passively Q‐Switched Yb:LuAG Single Crystal Fiber Laser

“…Single crystal fiber (SCF), combining the advantages of bulk crystal and glass fiber, has the characteristics of high thermal conductivity, superior laser damage threshold, high laser conversion efficiency, low thermal expansion coefficient, and good heat dissipation, making it an excellent gain medium for high power all-solid-state laser. [19][20][21][22][23] The various studies on Yb:LuAG bulk crystal lasers demonstrate that Yb:LuAG single crystal is a promising candidate for high-power lasers. [24][25][26] In our previous work, continuous wave (CW) laser output of up to 4.7 W was achieved by Yb:LuAG SCF, [27] however, there is little report on Yb:LuAG SCF pulsed laser.…”