A precious metal clay regeneration solution contains water and a liquid paraffin, in which an amount of the liquid paraffin is more than or equal to 0.12 parts by mass and less than or equal to 60 parts by mass with respect to 100 parts by mass of the water. A method for regenerating precious metal clay includes a step of bringing water and a liquid paraffin into contact with a solidified precious metal clay, in which an amount of the liquid paraffin is more than or equal to 0.12 parts by mass and less than or equal to 60 parts by mass with respect to 100 parts by mass of the water.

Thermoelectric materials based on tetrahedrite structures for thermoelectric devices and methods for producing thermoelectric materials and devices are disclosed.

A piezoelectric device has a piezoelectric ceramic layer obtained by sintering a piezoelectric ceramic composition that contains an alkali-containing niobate type perovskite composition which is represented by (Li.sub.lNa.sub.mK.sub.1-l-m).sub.n(Nb.sub.1-oTa.sub.o)O.sub.3 (wherein 0.04l0.1, 0m1, 0.95n1.05, 0o1) and Ag component, as well as a conductor layer sandwiching the piezoelectric ceramic layer. The piezoelectric ceramic layer has Ag segregated in voids present in a sintered compact of the perovskite composition in terms of oxides relative to the perovskite composition.

A voltage nonlinear resistor according to the present invention includes a sintered body consisting essentially of zinc oxide and containing bismuth, antimony, and boron as accessory components. The accessory components are bismuth oxide of 1.5 to 2.5 mol %, antimony oxide of 1 to 2 mol %, and boron oxide of 0.3 mol % or less in terms of oxides.

A ceramic multi-layer capacitor includes a main body, which has ceramic layers arranged along a layer stacking direction to form a stack, and first and second electrode layers arranged between the ceramic layers. The multi-layer capacitor also includes a first external contact-connection arranged on a first side surface of the main body and electrically conductively connected to the first electrode layers, and a second external contact-connection arranged on a second side surface of the main body. The second side surface is situated opposite the first side surface and is electrically conductively connected to the second electrode layers.

Thermoelectric materials based on tetrahedrite structures for thermoelectric devices and methods for producing thermoelectric materials and devices are disclosed.

A piezoelectric ceramic composition is represented by a composition formula A.sub.xBO.sub.3 and includes potassium sodium niobate containing K and Na that account for 80% or more of an amount of A-site elements and containing Nb that accounts for 70% or more of an amount of B-site elements. The piezoelectric ceramic composition contains Ta and Fe at a B-site.

A ceramic multi-layer capacitor includes a main body, which has ceramic layers arranged along a layer stacking direction to form a stack, and first and second electrode layers arranged between the ceramic layers. The multi-layer capacitor also includes a first external contact-connection arranged on a first side surface of the main body and electrically conductively connected to the first electrode layers, and a second external contact-connection arranged on a second side surface (62) of the main body (2). The second side surface is situated opposite the first side surface and is electrically conductively connected to the second electrode layers.

A piezoelectric ceramic composition contains a perovskite composition which is represented by (Pba.Math.Rex){Zr.sub.b.Math.Ti.sub.c, .Math.(Ni.sub.1/3Nb.sub.2/3).sub.d.Math.(Zn.sub.1/3Nb.sub.2/3).sub.e}O.sub.3 (wherein Re represents La and/or Nd, and a-e and x satisfy the following conditions 0.95a1.05, 0x0.05, 0.35b0.45, 0.35c0.45, 0<d0.10, 0.07e0.20 and b+c+d+e=1) and 0.05-0.3% by mass of an Ag component in terms of oxides relative to the perovskite composition.

A precious metal clay regeneration solution contains water and a liquid paraffin, in which an amount of the liquid paraffin is more than or equal to 0.12 parts by mass and less than or equal to 60 parts by mass with respect to 100 parts by mass of the water. A method for regenerating precious metal clay includes a step of bringing water and a liquid paraffin into contact with a solidified precious metal clay, in which an amount of the liquid paraffin is more than or equal to 0.12 parts by mass and less than or equal to 60 parts by mass with respect to 100 parts by mass of the water.