Revisiting AgCrSe<sub>2</sub>as a promising thermoelectric material

Wu, Di; Huang, Shitian; Feng, Dan; Li, Bing; Chen, Yuexing; Zhang, Jian; He, Jiaqing

doi:10.1039/c6cp04791b

Cited by 55 publications

(61 citation statements)

References 35 publications

(46 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The significance of the occupational disorder is also reflected in the difference between measured and calculated κL. The measured κL in literatures are different [11][12][13] and it is about 0.55 Wm -1 K -1 at room temperature in our measurement ( Fig. S13).…”

mentioning

confidence: 60%

“…They describe the transverse acoustic phonons, dynamic diffuse scattering, incoherent elastic scattering, and background, respectively. The much higher energy resolution, compared with the previous study 13 , allows us to investigate spectra in great details, in particular, the interplay between the dynamic diffuse scattering and the TA phonons.…”

Section: F) Inelastic Neutron Scatteringmentioning

confidence: 99%

“…a, Experimentally measured thermal conductivity as a function of temperature for two different samples of AgCrSe2. The thermal conductivity data from references (4) and (5) Ag 0.15184 (10) 0.0977 (13) 0.0123 (14) 0 Cr 0.00018(34) 0.0074 (5) 0.0052 (9) 0 Se1 0.26957 (16) 0.00673 (26) 0.0115 (4) 0 Se2 0.73310 (13) 0.00673 (26) 0.0115(4) 0 Table S2. The crystal structure data at 621 K. The space group is .…”

Section: Supplemental Figuresmentioning

confidence: 99%

See 2 more Smart Citations

Liquid-like thermal conduction in intercalated layered crystalline solids

et al. 2018

View full text Add to dashboard Cite

As a generic property, all substances transfer heat through microscopic collisions of constituent particles . A solid conducts heat through both transverse and longitudinal acoustic phonons, but a liquid employs only longitudinal vibrations. As a result, a solid is usually thermally more conductive than a liquid. In canonical viewpoints, such a difference also serves as the dynamic signature distinguishing a solid from a liquid. Here, we report liquid-like thermal conduction observed in the crystalline AgCrSe. The transverse acoustic phonons are completely suppressed by the ultrafast dynamic disorder while the longitudinal acoustic phonons are strongly scattered but survive, and are thus responsible for the intrinsically ultralow thermal conductivity. This scenario is applicable to a wide variety of layered compounds with heavy intercalants in the van der Waals gaps, manifesting a broad implication on suppressing thermal conduction. These microscopic insights might reshape the fundamental understanding on thermal transport properties of matter and open up a general opportunity to optimize performances of thermoelectrics.

show abstract

mentioning

confidence: 60%

Section: F) Inelastic Neutron Scatteringmentioning

confidence: 99%

Section: Supplemental Figuresmentioning

confidence: 99%

See 1 more Smart Citation

Liquid-like thermal conduction in intercalated layered crystalline solids

et al. 2018

View full text Add to dashboard Cite

show abstract

“…The piezoelectric coefficient for high‐resistance samples reaches 100–1000 pC N −1 at room temperature, which is comparable to that for typical piezoelectric crystals, e.g., BaTiO 3 , Pb(Mg 1/3 Nb 2/3 )O 3 ‐PbTiO 3 (PMN‐PT), and Pb(Zn 1/3 Nb 2/3 )O 3 ‐PbTiO 3 (PZN‐PT) . The large piezoelectric responses in AgCrSe 2 are attributed to collective displacements of Ag + ions driven by electric fields, since the isolated Ag + ions sandwiched by the CrSe 6 layers can be sensitively responded to applied electric fields . The present results indicate that polar semiconductors with high ionic conductivity could be promising piezoelectric materials, while such nonstoichiometric and conductive materials have been overlooked because of the apparently disadvantageous screening effect.…”

mentioning

confidence: 68%

Giant Piezoelectric Response in Superionic Polar Semiconductor

Shiomi

Akiba

Takahashi

et al. 2018

Adv Elect Materials

View full text Add to dashboard Cite

by lead zirconate titanate [Pb(Zr,Ti)O 3 or PZT],are the most widely used materials for applications. [5][6][7] From the viewpoint of the sustainable development of the world, many efforts have been devoted to the development of lead-free piezoelectric materials, [5][6][7] but its achievement is still challenging. Scientific research activities seem to be culminated, and a new guideline to a future research direction is required. [1] In this work, we newly propose a relatively conductive polar semiconductor as a potential piezoelectric material, although it has been believed that conduction electrons disfavor the formation of electric polarization. [8] AgCrSe 2 has a polar crystal structure of the R3m space group at room temperature, which allows piezoelectric effects. AgCrSe 2 crystallizes in a hexagonal structure with Ag layers and CrSe 6 octahedral layers stacking alternatively along the c axis, [9] as shown in Figure 1a. In between CrSe 6 layers, Ag + ions lie in one of the equivalent interstitial sites (α-sites and β-sites in Figure 1a), which are energetically degenerated. [9] It has been reported that the occupation of Ag + ions undergoes an order-to-disorder transition at 450-475 K (T OD ). In the disordered state above T OD , Ag + ions are distributed randomly in α and β sites with equal probability, whereas below T OD , only one of the interstitial sites is fully occupied, lowering the crystal symmetry from R-3m to R3m. Ag + ions are mobile in 2D space sandwiched by CrSe 6 layers, and the inplane ionic conductivity is high (≈ 3 × 10 −4 S cm −1[10] ) even at room temperature. Reflecting the disorder effect of Ag + ions, ultralow thermal conductivity due to strong phonon scatterings has been reported. [9,11,12] The thermoelectric Figure of merit of Ag 1-δ CrSe 2 is as large as ≈0.5 at 723 K, [12] which ensures that AgCrSe 2 is a promising thermoelectric material. [13] In this study, we report an excellent piezoelectric performance of AgCrSe 2 , by measuring the inverse piezoelectric effect, i.e., the generation of a strain upon application of an electric field, along the perpendicular direction to the conduction layers of AgCrSe 2 crystals. The carrier density of AgCrSe 2 was successfully controlled by subtle nonstoichiometry (presumably the Ag deficiency) dependent on the crystal growth conditions, which enables the study of the resistivity dependence of piezoelectric effect in this system. Though our AgCrSe 2 single crystals are not perfect insulators, we still observe large displacements of the crystals in response to A lead-free piezoelectric material whose performance is comparable to that of market-dominant lead-based ones has been strongly desired for the development of environmentally friendly piezoelectric devices. In spite of intensive research activities, however, few effective alternatives have been found due to severe requirements such as the absence of conducting carriers screening the electric polarization. Here, a polar semiconductor, AgCrSe 2 , is demonstrated as a promising piezoelectri...

show abstract

“…Recently, a class of “liquid‐like” TE materials with complex phase transitions, ultralow lattice thermal conductivity, and liquid‐like ionic conduction have been reported, Cu 2− x (S, Se, Te), [ 19–21 ] Ag 2 (S, Se, Te), [ 22,23 ] argyrodite, [ 24–36 ] AgCrSe 2 , [ 37,38 ] CuAgSe, [ 39 ] and AgCuTe [ 40 ] to name a few. Argyrodites are good examples of liquid‐like TE materials.…”

Section: Introductionmentioning

confidence: 99%

High Thermoelectric Performance in Sulfide‐Type Argyrodites Compound Ag₈Sn(S₁₋_xSe_x)₆ Enabled by Ultralow Lattice Thermal Conductivity and Extended Cubic Phase Regime

Shen

Xia

Yang

et al. 2020

Adv Funct Materials

View full text Add to dashboard Cite

Argyrodites with a general chemical formula of A 8 BC 6 are known for complex phase transitions, ultralow lattice thermal conductivity, and mixed electronic and ionic conduction. The coexistence of ionic conduction and promising thermoelectric performance have recently been reported in selenide and telluride argyrodites, but scarcely in sulfide argyrodites. Here, the thermoelectric properties of Ag 8 Sn(S 1−x Se x ) 6 are reported. Specifically, Ag 8 SnS 6 exhibits intrinsically ultralow lattice thermal conductivities of 0.61-0.31 W m −1 K −1 over the whole temperature range from 32 to 773 K due to distorted local crystal structure, relatively weak chemical bonding, rattler-like Ag atoms, low-lying optical modes, and dynamic disorder of Ag ions at high temperatures. Se doping shifts the orthorhombic-cubic phase transition from 457 K at x = 0 to 430 K at x = 0.10, thereby expanding the temperature range of the thermoelectrically favored cubic phase. A figure of merit zT value ≈ 0.80 is achieved at 773 K in Ag 8 Sn(S 1−x Se x ) 6 (x = 0.03), the highest zT value reported in sulfide argyrodites. These results fill a knowledge gap of the thermoelectric study of argyrodites and contribute to a comprehensive understanding of the chemical bonding, lattice dynamics, and thermal transport of argyrodites.a potential for practical applications. Yet, it is still a challenge to decouple the adversely correlated {σ, S, κ e } toward high zT values via electronic and phonon band engineering. [3][4][5][6][7][8] Many efforts have been devoted to discover novel TE materials such as cage-like filled skutterudites (e.g., CeFe 4 Sb 12 , CoSb 3 , Sr 8 Ga 16 Ge 30 , etc.), [9][10][11][12] Zintl-phase compounds (e.g., CaZn 2 Sb 2 , Mg 3 Sb 2 , YbMg 2 Bi 2 , etc.), [13][14][15][16] and defective half-Heusler compounds (e.g., Nb 0.8 CoSb, Ti 0.9 NiSb, V 0.9 CoSb, etc.) [17] that possess a long-range order favoring charge carrier mobility while disordered in short range to inhibit heat-carrying phonons in the context of "phonon-glass-electron-crystal". [18] Recently, a class of "liquid-like" TE materials with complex phase transitions, ultralow lattice thermal conductivity, and liquidlike ionic conduction have been reported, Cu 2−x (S, Se, Te), [19][20][21] Ag 2 (S, Se, Te), [22,23] argyrodite, [24][25][26][27][28][29][30][31][32][33][34][35][36] AgCrSe 2 , [37,38] CuAgSe, [39] and AgCuTe [40] to name a few. Argyrodites are good examples of liquid-like TE materials. Argyrodites include 716, 816, and 916 phases in chemistry, with a general chemical formula A 12−n

show abstract

Revisiting AgCrSe₂as a promising thermoelectric material

Cited by 55 publications

References 35 publications

Liquid-like thermal conduction in intercalated layered crystalline solids

Liquid-like thermal conduction in intercalated layered crystalline solids

Giant Piezoelectric Response in Superionic Polar Semiconductor

High Thermoelectric Performance in Sulfide‐Type Argyrodites Compound Ag₈Sn(S₁₋_xSe_x)₆ Enabled by Ultralow Lattice Thermal Conductivity and Extended Cubic Phase Regime

Contact Info

Product

Resources

About

Revisiting AgCrSe2as a promising thermoelectric material

Cited by 55 publications

References 35 publications

Liquid-like thermal conduction in intercalated layered crystalline solids

Liquid-like thermal conduction in intercalated layered crystalline solids

Giant Piezoelectric Response in Superionic Polar Semiconductor

High Thermoelectric Performance in Sulfide‐Type Argyrodites Compound Ag8Sn(S1−xSex)6 Enabled by Ultralow Lattice Thermal Conductivity and Extended Cubic Phase Regime

Contact Info

Product

Resources

About

Revisiting AgCrSe₂as a promising thermoelectric material

High Thermoelectric Performance in Sulfide‐Type Argyrodites Compound Ag₈Sn(S₁₋_xSe_x)₆ Enabled by Ultralow Lattice Thermal Conductivity and Extended Cubic Phase Regime