We report evidence of the absence of zero thermal expansion in well-characterized high-quality polycrystalline samples of YbGaGe. High-quality samples of YbGaGe were produced from high-purity starting elements and were extensively characterized using x-ray powder diffraction, differential thermal analysis, atomic emission spectroscopy, magnetization, and neutron powder diffraction at various te...

The creation of a surface breaks the translational symmetry of the bulk with the electrons redistributing to lower their energy, resulting in a new lattice structure. Surface relaxation and reconstruction have been studied for years, and it is generally assumed that theory and experiment are in fairly good agreement for the ground state properties at a metal surface. There is a conceptual pictu...

Thermal expansion is an important property of substances. Its theoretical prediction has been challenging, particularly in cases the volume decreases with temperature, i.e., thermal contraction or negative thermal expansion at high temperatures. In this paper, a new theory recently developed by the authors has been reviewed and further examined in the framework of fundamental thermodynamics and...

The control of thermal expansion of solid compounds is intriguing but remains challenging. The effect of guests on the thermal expansion of open-framework structures was investigated. Notably, the presence of guest ions (K+ ) and molecules (H2 O) can substantially switch thermal expansion of YFe(CN)6 from negative (αv =-33.67×10-6  K-1 ) to positive (αv =+42.72×10-6  K-1 )-a range that covers t...

In this study, Thermal expansion coefficient (TEC) variation of Ln0.6Sr0.4Co0.2M0.8O3−δ (Ln=La,Nd,Sm and M= Fe,Ni,Mn) perovskite oxide have been evalouated. Different compounds have been prepared and thermal expansion coefficient have been meseaured in different temperature by means of dilatometer analysis. Structural parameters of compounds have been  determined by X-ray diffraction and Field ...

The use of strain gages for low temperature thermal expansion measurements is increasing, due to it's convenience, and relative accuracy. The determination of thermal expansion with strain gages is complicated by "thermal output strain", a phenomena caused by the temperature dependence of the gage. If thermal output strain is properly compensated , strain gages may be used to measure thermal ex...

Size effects on Volume thermal expansion of nanomaterials. The experimental measurements show that volume thermal expansion of nanosolids is larger than those of their bulk counterparts. On considering the surface effect, a simple model is derived to study the size dependence of volume thermal expansion of nanomaterials for spherical nanoparticles, nanowire and nanofilms. The size dependence of...

Controlling the thermal expansion of materials is of great technological importance. Uncontrolled thermal expansion can lead to failure or irreversible destruction of structures and devices. In ordinary crystals, thermal expansion is governed by the asymmetry of the microscopic binding potential, which cannot be adjusted easily. In artificial crystals called metamaterials, thermal expansion can...

Abstract. Cubic crystalline oxides such as Y2O3 and MgO is used to stabalized zirconia phases at high temperature. In this paper the Y2O3 powder was added to stabilized zirconia and preparing a mixture of MgAl2O4 Spinel by mixing 1mol of nano-MgO with 1 mol of nano-Al2O3 powders. The spinel was added to the Y2O3-ZrO2 by various weight percentage (5, 10, 15, 20 and 25 wt%), and after that the sp...