A glass includes a first glass portion and a second glass portion. The first glass portion has a higher ion packing density than the second glass portion (has a composition that forms a glass in which, out of plastic deformation characteristics, plastic flow is dominant). The second glass has a lower ion packing density than the first glass portion (has a composition that forms a glass in which, out of the plastic deformation characteristics, densification is dominant).

A substrate for a flexible device which includes a stainless steel sheet, a nickel plating layer formed on a surface of the stainless steel sheet, and a glass layer of electrical insulating bismuth-based glass formed in the form of layer on a surface of the nickel plating layer.

A substrate for a flexible device which includes a stainless steel sheet, a nickel plating layer formed on a surface of the stainless steel sheet, and a glass layer of electrical insulating bismuth-based glass formed in the form of layer on a surface of the nickel plating layer.

A composite ceramic powder of the present invention includes: a LAS-based ceramic powder having precipitated therein -eucryptite or a -quartz solid solution as a main crystal; and TiO.sub.2 powder and/or ZrO.sub.2 powder.

The present invention provides a ceramic powder, in which -eucryptite or a -quartz solid solution is precipitated as a main crystal phase, and which includes TiO.sub.2 and/or ZrO.sub.2.

The present invention provides a ceramic powder, in which -eucryptite or a -quartz solid solution is precipitated as a main crystal phase, and which includes TiO.sub.2 and/or ZrO.sub.2.

A cover glass for a hermetic package includes a sealing material layer on one surface. The sealing material layer satisfies one of the following relationships (1) to (6) between its center line length (L.sub.CL) and average width (W.sub.A): (1) when L.sub.CL is 150 mm or more, W.sub.A is 0.20% or more of L.sub.CL; (2) when L.sub.CL is 100 mm or more and less than 150 mm, W.sub.A is 0.30% or more of L.sub.CL; (3) when L.sub.CL is 75 mm or more and less than 100 mm, W.sub.A is 0.35% or more of L.sub.CL; (4) when L.sub.CL is 50 mm or more and less than 75 mm, W.sub.A is 0.40% or more of L.sub.CL; (5) when L.sub.CL is 25 mm or more and less than 50 mm, W.sub.A is 0.60% or more of L.sub.CL; and (6) when L.sub.CL is less than 25 mm, W.sub.A is 0.90% or more of L.sub.CL.

Provided is a ceramic powder having precipitated therein -eucryptite or a -quartz solid solution as a main crystal phase, having an average particle diameter D.sub.50 of 20 m or less, and having a negative thermal expansion coefficient in a range of from 30 C. to 300 C.

Disclosed in the present invention is a beam coherence eliminating element. The optical medium material of the element comprises microcrystalline glass, wherein microcrystalline particles therein have a size of 0.1-1000 nm and are distributed randomly. As the crystals in the microcrystalline glass can change the phase of light beams, the microcrystalline glass can change the phase of the light beams randomly, thereby eliminating the coherence of the beams. The crystal size of the microcrystalline glass is small, and thus does not affect the transmission efficiency of light beams. The element of the present invention has a simple structure and is convenient to use, and can be added in the process of beam transmission to easily eliminate beam coherence

Provided is a conductive paste for forming a solar cell electrode containing a glass frit component (A) as glass frit (II), the glass frit component (A) containing the following in the content ratio to the total molar number in terms of oxide: (a) 30 to 70 mol % of tellurium element, (b) 18 to 30 mol % of tungsten element, (c) 5 to 30 mol % of zinc element, (d) 1 to 15 mol % of boron element, (e) 0.3 to 5 mol % of aluminum element, (f) 0.3 to 7 mol % of one or more selected from rare earth elements in terms of oxide, and (g) 0.1 to 7 mol % of one or more selected from the group consisting of tin, lithium, and barium elements in terms of oxide.

The conductive paste may have better electric characteristics and a small variation in the characteristics even at a relatively low firing temperature (for example, 760 C.).