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Your search keyword '"Lian, Yu-Kun"' showing total 10 results
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10 results on '"Lian, Yu-Kun"'

1. Spin glass state in layered compound MnSb2Te4

Author

Li, Hao, Li, Yaoxin, Lian, Yu-Kun, Xie, Weiwei, Chen, Ling, Zhang, Jinsong, Wu, Yang, and Fan, Shoushan

Subjects
Condensed Matter - Materials Science
Abstract

As a sister compound and isostructural of MnBi2Te4, the high quality MnSb2Te4 single crystals are grown via solid-state reaction where prolonged annealing and narrow temperature window play critical roles on account of its thermal metastability. X-ray diffraction analysis on MnSb2Te4 single crystals reveals pronounced cation intermixing, 28.9(7)% Sb antisite defects on the Mn (3a) site and 19.3(6)% Mn antisite defects on the Sb (6c) site, compared with MnBi2Te4. Unlike antiferromagnetic (AFM) nature MnBi2Te4, MnSb2Te4 contains magnetic and antiferromagnetic competition and exhibits a spin glass (SG) state below 24 K. Its magnetic hysteresis, anisotropy, and relaxation process are investigated in detail with DC and AC magnetization measurements. Moreover, anomalous Hall effect as a p-type conductor is demonstrated through transport measurements. This work grants MnSb2Te4 a possible access to the future exploration of exotic quantum physics by removing the odd/even layer number restraint in intrinsic AFM MnBi2Te4-family materials as a result of the crossover between its magnetism and potential topology in the Sb-Te layer., Comment: 14 Pages, 5 figures

Published
2021

8. A2SnS5: A Structural Incommensurate Modulation Exhibiting Strong Second‐Harmonic Generation and a High Laser‐Induced Damage Threshold (A=Ba, Sr).

Author

Li, Rui‐An, Zhou, Zhengyang, Lian, Yu‐Kun, Jia, Fei, Jiang, Xingxing, Tang, Ming‐Cong, Wu, Li‐Ming, Sun, Junliang, and Chen, Ling

Subjects
CHARGE density waves, SECOND harmonic generation, ALKALINE earth metals, STRONTIUM, OPTICAL properties, THERMAL expansion, NONLINEAR optics
Abstract

Structural modulations have been recently found to cause some unusual physical properties, such as superconductivity or charge density waves; however, thus‐induced nonlinear optical properties are rare. We report herein two unprecedented incommensurately modulated nonlinear optical sulfides exhibiting phase matching behavior, A2SnS5 (A=Ba, Sr), with the (3+1)D superspace groups P21212(00γ)00s or P21(α0γ)0, featuring different modulations of the [Sn2S7]∞ belts. Remarkably, Ba2SnS5 exhibits an excellent second harmonic generation (SHG) of 1.1 times that of the benchmark compound AgGaS2 at 1570 nm and a very large laser‐induced damage threshold (LIDT) of 8×AgGaS2. Theoretical studies revealed that the structural modulations increase the distortions of the Sn/S building units by about 44 or 25 % in A2SnS5 (A=Ba, Sr), respectively, and enhance significantly the SHG compared with α‐Ba2SnSe5 without modulation. Besides, despite the smaller Eg, the A2SnS5 samples exhibit higher LIDTs owing to their smaller thermal expansion anisotropies (Ba2SnS5 (1.51)

Published
2020
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9. Sr6(Li2Cd)A4S16(A = Ge, Sn): How to Go beyond the Band Gap Limitation via Site-Specific Modification

Author

Lian, Yu-Kun, Li, Rui-An, Liu, Xin, Wu, Li-Ming, and Chen, Ling

Abstract

Band gap tuning is at the core of current optical and electronic device applications, the wide-band-gap chalcogenides are especially challenging and highly desired in many fields, such as nonlinear optical materials. On the basis of our in-depth investigation on the complicated cubic AII6(BI2CII)DIV4S16family, we reveal that the structural complexity causes the band gap tuning to be determined by multiple factors, in which a “bucket effect” is uncovered. Guided by such a bucket effect strategy, we rationally synthesized two new members, Sr6(Li2Cd)A4S16(A = Ge (1; a= 13.916 Å), Sn (2; a= 14.237 Å), via a site-specific substitution. 1exhibits the widest band gap (3.8 eV) in this family known to date. Benefiting from their wide band gaps, 1and 2exhibit excellent laser irradiation duration capability, with laser-induced damage thresholds (LIDTs) of 55.5 and 44.4 MW/cm2at a 1.064 μm incident laser, which are 21 and 17 times higher than that of the benchmark AgGaS2(2.69 MW/cm2). Especially, the LIDT of 1is the highest known to date among the cubic AII6BI2CIIDIV4S16family. Our insight into the band gap tuning in a complex system should shed useful light on the future design of functional materials and band gap engineering.

Published
2020
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