Giant negative thermal expansion at the nanoscale in the multifunctional material 
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Belo, João H.; Pires, Ana L.; Gomes, I. T.; Andrade, Vivian M.; Sousa, J. B.; Hadimani, Ravi L.; Jiles, David; Ren, Yang; Zhang, Xiaoyi; Araújo, João P.; Pereira, A. M.

doi:10.1103/physrevb.100.134303

Cited by 28 publications

(27 citation statements)

References 41 publications

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“…The negative thermal expansion has become an important feature of materials properties, as represented by the progressive increase of works on such a theme. It can be mentioned the case of ScF 3 , NpFeAsO, (Al 0.2 Zr 0.8 ) 20/19 Nb(PO 4 ) 3 , and Gd 5 (Si,Ge) 4 …”

Section: Results and Discussionmentioning

confidence: 99%

“…It can be mentioned the case of ScF 3 , 47 NpFeAsO, 48 (Al 0.2 Zr 0.8 ) 20/19 Nb(PO 4 ) 3 , 49 and Gd 5 (Si,Ge) 4 . 50 A local structure analysis was performed based on the distances (d 1 and d 2 ) and angles (θ 213 and θ 145 ) and their dependence with temperature. A sketch of a small local unit showing BP angles and distances is represented in Figure 2d.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

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Structural Features, Anisotropic Thermal Expansion, and Thermoelectric Performance in Bulk Black Phosphorus Synthesized under High Pressure

et al. 2020

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Black phosphorus (BP) allotrope has an orthorhombic crystal structure with a narrow bandgap of 0.35 eV. This material is promising for 2D technology since it can be exfoliated down to one single layer: the well-known phosphorene. In this work, bulk BP was synthesized under high-pressure conditions at high temperatures. A detailed structural investigation using neutron and synchrotron X-ray diffraction revealed the occurrence of anisotropic strain effects on the BP lattice; the combination of both sets of diffraction data allowed visualization of the lone electron pair 3s 2 . Temperature-dependent neutron diffraction data collected at low temperature showed that the a axis (zigzag) exhibits a quasi-temperature-independent thermal expansion in the temperature interval from 20 up to 150 K. These results may be a key to address the anomalous behavior in electrical resistivity near 150 K. Thermoelectric properties were also provided; low thermal conductivity from 14 down to 6 Wm −1 K −1 in the range 323−673 K was recorded in our polycrystalline BP, which is below the reported values for singlecrystals in literature.

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Section: Results and Discussionmentioning

confidence: 99%

Section: ■ Experimental Sectionmentioning

confidence: 99%

Structural Features, Anisotropic Thermal Expansion, and Thermoelectric Performance in Bulk Black Phosphorus Synthesized under High Pressure

et al. 2020

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“…[14] A negative CTE can appear as a result of a decrease in the size of nanoparticles caused by internal surface pressure. [15] Various mechanisms for the realization of NTE are described in the review; [16] some are associated with transverse acoustic modes, while others with the rotation of rigid polyhedral groups of atoms.…”

Section: Introductionmentioning

confidence: 99%

Negative Thermal Expansion of Carbon Nanotube Bundles

Galiakhmetova

Korznikova

Kudreyko

2021

Physica Rapid Research Ltrs

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A bundle of aligned carbon nanotubes (CNTs) under lateral loading and heating is considered under plane strain conditions within the framework of a molecular dynamics model with a reduced number of degrees of freedom. Bundles of CNTs of sufficiently large diameter exhibit negative lateral thermal expansion. The coefficient of thermal expansion is practically constant up to a temperature of 1500 K and practically does not depend on biaxial lateral compression up to a volumetric compressive strain of 0.06. This anomalous behavior is explained by the two mechanisms: elliptization of the CNT cross section and bending of the CNT walls by thermal fluctuations. Elliptization leads to a decrease in the cross‐sectional area of the CNT, and the bending of the CNT wall leads to a decrease in the effective diameter of the CNT. A bundle with CNTs of the largest investigated diameter demonstrates a large negative coefficient of linear thermal expansion, K−1, which is weakly dependent on temperature.

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“…This is called the quantum revolution 1.0 and we are in the beginning of quantum revolution 2.0. Currently many new materials exhibit exotic properties like, unconventional superconductivity [1,2], room temperature superconductivity [3][4][5], reduced magnetism [6,7], reduced Pauli repulsion [8], giant negative thermal expansion [9] and unconventional ferroelectricity [10]. These exotic properties could not be explained completely with the existing quantum mechanical theory which is mysterious yet incredibly accurate.…”

Section: Introductionmentioning

confidence: 99%

Probing the Private Quantum Life of s Electrons in Atoms of Nanomaterials -A New Quantum Theoretical Insight

Iyakutti¹,

Vj²

2021

Preprint

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The exotic properties exhibited by some of the nanomaterials could not be explained by the existing quantum theory. As a result one is forced to look back at the development of the quantum theory and some of the inelegancies. First, the quantized orbital angular momentum of s electron in an atom is taken as zero. This may be an acceptable fact for s electrons in an individual atom, but for the s electrons in a crystal or nanomaterial, this is far from the real situation. Secondly, in the wave function Ψ(r,θ), θ is considered as a dimensionless variable. These inelegancies lead to the impression that the present quantum theory is a steppingstone to a more complete description of nature. Here arises a necessity for probing the private quantum life of s electrons in crystal or nanomaterial. By assigning dimension to θ on par with r, we have quantum engineered the orbital angular momentum and hence the orbital degrees of freedom of s electrons and their signatures in a crystal. This restoration leads to new non-zero angular quantum numbers to s electrons of atoms in a crystal/nanomaterial. As a result the s electron occupation in nanomaterial is altered. Its new physics implications in material science, quantum chemistry and quantum technology are highlighted in this paper.

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Giant negative thermal expansion at the nanoscale in the multifunctional material Gd5(Si,Ge)4

Cited by 28 publications

References 41 publications

Structural Features, Anisotropic Thermal Expansion, and Thermoelectric Performance in Bulk Black Phosphorus Synthesized under High Pressure

Structural Features, Anisotropic Thermal Expansion, and Thermoelectric Performance in Bulk Black Phosphorus Synthesized under High Pressure

Negative Thermal Expansion of Carbon Nanotube Bundles

Probing the Private Quantum Life of s Electrons in Atoms of Nanomaterials -A New Quantum Theoretical Insight

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