Abstract: A lead-free solder composition having superior mechanical strength is produced by adding a rare earth element to a Sn—Ag alloy or a Sn—Ag—Bi—Cu alloy.

Abstract: New and improved substantially lead-free solder compositions are provided exhibiting excellent wettability and mechanical properties. In an embodiment, an improved solder material is a substantially silver-free material including from about 0.5 to about 10% by weight of Zn, from about 0.5 to about 8% by weight of Bi, from about 0.005 to about 0.5% by weight of Ge, from about 0.3 to about 3% by weight of Cu and the balance to make 100% by weight of Sn. In another embodiment, an improved solder material includes from about 0.5 to 8% by weight of Bi, from about 0.5 to about 3% by weight of Ag, from about 0.01 to about 0.1% by weight of Ge, from about 0.3 to about 1% by weight of Cu, and the balance to make 100% by weight of Sn. In a further embodiment, an improved solder material includes from about 3 to about 15% by weight of Zn, from about 3 to about 10% by weight of In, from about 0.01 to about 0.3% by weight of Ge, from about 0.3 to about 3% by weight of Ag and the balance to make 100% by weight of Sn.

Abstract: A lead-free solder composition having superior mechanical strength is produced by adding a rare earth element to a Sn—Ag alloy or a Sn—Ag—Bi—Cu alloy. The rare earth element is Sm, Gd, or a mixture of these elements with other rare earth elements.

Abstract: A lead-free solder composition having superior mechanical strength is produced by adding a rare earth element to a Sn-Ag alloy or a Sn-Ag-Bi-Cu alloy.

Abstract: A method is provided for producing a KTiOPO.sub.4 which is grown at a temperature higher than its Curie temperature using a TSSG method. The grown KTiOPO.sub.4 single crystal is maintained in contact with a melt while the crystal is maintained at a temperature higher than the Curie temperature. A d.c. current is applied in this state across a seed crystal and the melt, while the single crystal is cooled to a temperature lower than the Curie temperature. The value of current density D, defined by the formula D=Ip/(a+b), where Ip is the impressed current and a, b are crystal sizes along a and b axes, respectively, is selected to be 0.01 mA/cm.sup.2 .ltoreq.D.ltoreq.1.0 mA/cm.sup.2. In this manner, the produced KTiOPO.sub.4 is processed into a single domain crystal.

Abstract: An optomagnetic recording medium utilizing both rare earth metals and transition metals in the optomagnetic recording system. From 15 to 35 atomic % of the recording medium on the nonmagnetic base consists of one of the rare earth metals gadolinium (Gd), terbium (Tb) or dysprosium (Dy) with the balance being an alloyed mixture of iron (Fe), cobalt (Co) and germanium (Ge). The optomagnetic recording material of the present invention has an increased phase transition temperature without a rise in its Curie point, and provides satisfactory recording and erasing under temperature conditions up to near the Curie point.