Temperature‐Induced Abrupt Volume Inflation in the Mixed‐Valence Ternary Zintl Phase Yb8Ge3Sb5.

The unusual property of negative thermal expansion is of fundamental interest and may be used to fabricate composites with zero or other controlled thermal expansion values. Here we report that colossal negative thermal expansion (defined as linear expansion <−10−4 K−1 over a temperature range ~100 K) is accessible in perovskite oxides showing charge-transfer transitions. BiNiO3 shows a 2.6% volume reduction under pressure due to a Bi/Ni charge transfer that is shifted to ambient pressure through lanthanum substitution for Bi. Changing proportions of coexisting low- and high-temperature phases leads to smooth volume shrinkage on heating. The crystallographic linear expansion coefficient for Bi0.95La0.05NiO3 is −137×10−6 K−1 and a value of −82×10−6 K−1 is observed between 320 and 380 K from a dilatometric measurement on a ceramic pellet. Colossal negative thermal expansion materials operating at ambient conditions may also be accessible through metal-insulator transitions driven by other phenomena such as ferroelectric orders.

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“… 9 ), and Yb 8 Ge 3 Sb 5 (ref. 10 ), but the volume usually collapses over a narrow interval at low temperatures with strong hysteresis.…”

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confidence: 99%

Colossal negative thermal expansion in BiNiO3 induced by intermetallic charge transfer

et al. 2011

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“…The materials with anisotropic mechanical, magnetic, optical, and elastic properties are well-exploited, but the materials with intrinsic anisotropic thermal properties are very rare. Rare earth based intermetallics are noteworthy in this direction; YbGaGe, 2 Yb 4 TGe 8 (T = Cr, Ni, and Ag), 12 and Yb 8 Ge 3 Sb 5 13 are a few examples reported with anisotropic TE and noncubic systems with intrinsic anisotropic thermal properties (PTE, ZTE, or NTE) need to be discovered. The measure of expansion in a material is given by its coefficient of thermal expansion (CTE).…”

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confidence: 99%

Anisotropic Near-Zero Thermal Expansion in REAg_xGa_4–x (RE = La–Nd, Sm, Eu, and Yb) Induced by Structural Reorganization

et al. 2018

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In this work, we have discovered the anisotropic near Zero Thermal Expansion (NZTE)_ behavior in a family of compounds REAgxGa4-x (RE = LaNd , Sm, Eu and Yb). The compouds adopts CeAl2Ga2 structure type. were obtained as single crystals in high yield by metal flux growth technique using gallium as active flux. Synthesized compounds with space group I4/mmm. Temperature dependent single crystal X-ray diffraction suggests that all the compounds exhibit zero thermal expansion along c direction in the temperature range of 100-450 K. Temperature dependent X-Ray absorption near edge spectroscopic study confirmed ZTE behavior is due to the geometrical features associated within the crystal structure. The anisotropic NZTE behavior was further established by anisotropic magnetic measurements on selected single crystals. The atomic displacement parameters, apparent bond lengths, bond angles, and structural distortion with respect to the temperature reveal that geometric features associated with the structural distortion cause the anisotropic NZTE along c-direction. The preliminary magnetic studies suggest all the compounds are paramagnetic at room temperature except LaAgGa3. Electrical resistivity study reveals that compounds from this series are metallic in nature.

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Temperature‐Induced Abrupt Volume Inflation in the Mixed‐Valence Ternary Zintl Phase Yb₈Ge₃Sb₅.

Cited by 2 publications

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Colossal negative thermal expansion in BiNiO3 induced by intermetallic charge transfer

Colossal negative thermal expansion in BiNiO3 induced by intermetallic charge transfer

Anisotropic Near-Zero Thermal Expansion in REAg_xGa_4–x (RE = La–Nd, Sm, Eu, and Yb) Induced by Structural Reorganization

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Temperature‐Induced Abrupt Volume Inflation in the Mixed‐Valence Ternary Zintl Phase Yb8Ge3Sb5.

Cited by 2 publications

References 1 publication

Colossal negative thermal expansion in BiNiO3 induced by intermetallic charge transfer

Colossal negative thermal expansion in BiNiO3 induced by intermetallic charge transfer

Anisotropic Near-Zero Thermal Expansion in REAgxGa4–x (RE = La–Nd, Sm, Eu, and Yb) Induced by Structural Reorganization

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Temperature‐Induced Abrupt Volume Inflation in the Mixed‐Valence Ternary Zintl Phase Yb₈Ge₃Sb₅.

Anisotropic Near-Zero Thermal Expansion in REAg_xGa_4–x (RE = La–Nd, Sm, Eu, and Yb) Induced by Structural Reorganization