Pressure-tuning structural and electronic transitions in semimetal CoSb

Jiang

et al. 2023

Chem. Mater.

Materials capable of switching in multiple states under external stimuli have garnered extensive attention in the field of memory devices and switches. The coupling of various switching properties is of paramount significance to the creation of multifunctional devices. Herein, we report the pressure-induced multiswitching behaviors of both the structural and physical properties in two chromium selenides, CrSe and Cr2Se3. Comprehensive high-pressure characterizations reveal the collaborative occurrence of pressure-induced structural phase transitions, spin-crossover, metallization, and n–p conduction-type switching in both compounds. Upon compression, Cr2Se3 demonstrates an unexpected increase in resistivity and band gap, which is associated with the disordering of the self-intercalation structure. Of particular interest is that due to the dimensional differences in crystal structures, the photoelectric properties of the two decompressed samples are inversely regulated after pressure treatment. Notably, the band gap of Cr2Se3 is pronouncedly broadened after decompression due to the partially irreversible disorder in the structure. These results demonstrate that pressure engineering can regulate the photoelectric properties of materials effectively and flexibly, serving as a potential foundation for fabricating innovative pressure-responsive multifunctional devices.

Section: ■ Introductionmentioning

confidence: 99%

“…NiAs-type compounds tend to undergo structural phase transitions to the MnP-type structure under HP, including MnAs, MnTe, CrTe, and CoSb . This atomic-shift-type (i.e., martensitic) phase transition always leads to abrupt changes in both the electrical and magnetic properties of materials.…”

Section: Introductionmentioning

confidence: 99%

Pressure-Induced Reversible and Irreversible Multistate Switching in NiAs-Type Chromium Selenides

Jiang

et al. 2023

Chem. Mater.

“…As a cleaning method, pressure can effectively modulate the crystal structure of compounds by adjusting bond lengths, bond angles, and space groups, leading to numerous fascinating physical phenomena in materials. − Many NiAs-type compounds have been reported to undergo structural phase transitions to the MnP-type structure under high pressure (HP). ,− At room temperature, MnAs undergoes a NiAs-to-MnP phase transition at 1.22 kbar, accompanied by a high-spin-to-low-spin transition of Mn . In CoSb, an n–p switching appears along with structural phase transition . For the Cr–Te system, different defective NiAs-type structures provide an ideal platform to study the structure–property relationship of materials.…”

Section: Introductionmentioning

confidence: 99%

Pressure-Induced Structural Phase Transition, Anomalous Insulator-to-Metal Transition, and n–p Conduction-Type Switching in Defective, NiAs-Type Cr_1−δTe

Jin

et al. 2022

Inorg. Chem.

Cr1−δTe, as a unique series of defective compounds with a NiAs-type structure and periodic metal vacancies, has attracted intensive research interest because of its diversity in structure and property dependent on the tunable stoichiometric ratio. Another feature of these compounds is their ability to switch between NiAs- and MnP-type structures, in which there often exist composition-, temperature-, or pressure-induced phase transitions accompanied by intriguing physical property switching. Herein, we report the syntheses of a series of Cr1−δTe compounds with similar compositions but distinct crystal structures, their phase transitions, anomalous transport, and photoelectric conduction behaviors under high pressure (HP). For the three Cr1−δTe compounds with δ = 0, 0.25, 0.375, CrTe undergoes pressure-induced NiAs-to-MnP phase transition at around 15 GPa, while Cr3Te4 and Cr5Te8 undergo isostructural phase transitions at around 12 and 11 GPa, respectively. Electrical transport measurements indicate anomalous conduction behaviors: CrTe undergoes a semiconductor-to-metal transition at around 24 GPa, while Cr3Te4 and Cr5Te8 show unexpected metal–semiconductor–metal transitions sequentially upon compression. Besides, CrTe and Cr5Te8 exhibit pressure-induced n–p conduction-type switching at around 9 and 3 GPa, respectively, while Cr3Te4 shows p-type conductivity in the full pressure range. Local structure analyses based on in situ HP Raman spectra are performed to understand the structure and property evolutions of Cr1−δTe under HP. Defective transition-metal chalcogenides with pressure-induced NiAs-to-MnP phase transition and conduction-type conversion provide a potential platform for the rational design of photoelectric conversion devices.

“…As an important thermodynamic parameter as temperature, pressure can remarkably modulate the crystal structures and physical properties of materials by changing crystallographic parameters such as bond length and bond angle . Under high pressure (HP), the materials can exhibit a series of binary conversions of physical properties, such as spin-crossover, , piezochromism, , and metal–insulator transition. , In addition, pressure-driven n – p switching has also gradually attracted research interest, which mainly occurs in materials such as elements, , metal oxides, , chalcogenides, − and pnictides. , Among them, there is one class of pressure-driven n – p switching that essentially originates from electronic transitions, typically as the Fermi surface topological changes known as Lifshitz transitions, e.g. , in Bi 2 Te 3 , while the other class is related to pressure-induced structural phase transitions, e.g.…”

Section: Introductionmentioning

confidence: 99%

“…15,16 In addition, pressure-driven n−p switching has also gradually attracted research interest, which mainly occurs in materials such as elements, 17,18 metal oxides, 19,20 chalcogenides, 21−25 and pnictides. 26,27 Among them, there is one class of pressuredriven n−p switching that essentially originates from electronic transitions, typically as the Fermi surface topological changes known as Lifshitz transitions, e.g., in Bi 2 Te 3 , 24 while the other class is related to pressure-induced structural phase transitions, e.g., in CuFeS 2 . 21 The latter tends to be reversible, as is temperature-induced n−p switching.…”

Section: ■ Introductionmentioning

confidence: 99%

Rewritable Pressure-Driven n–p Conduction Switching in Marcasite-Type CrSb₂

Peng

et al. 2023

Chem. Mater.

Temperature-or pressure-driven n−p conductiontype switching has been described as an emerging phenomenon for potential applications as transistors, switches, and memory devices.The key challenge in the development of such n−p conductiontype switching materials is to establish maneuverable and controllable methods to achieve easy convertibility and nonvolatility. Herein, we report the first example of rewritable pressure and temperature dual-controlled n−p conduction-type switching in marcasite-type CrSb 2 . At room temperature, CrSb 2 exhibits an unexcepted pressure-driven n−p conductivity-type switching around 12 GPa accompanied by a marcasite-to-arsenopyrite structural transition and a semiconductor-to-metal transition. The dramatic conduction-type switching is irreversible after pressure releasing at room temperature but reversible by annealing at a relatively low temperature (>80 °C). Accordingly, a multicycle bistability switching process is established under the dual regulation of both pressure and temperature. The underlying structure− property mechanism is revealed by in situ/ex situ characterization and analyses of the atomic-level microstructure, local lattice distortion, and residual stress induced by compression. This demonstration provides a new platform for the rational design of rewritable temperature/pressure-responsive photoelectric conversion devices.