Tin telluride Tin telluride Tin telluride is a compound of tin and tellurium (SnTe); is a IV-VI narrow band gap semiconductor and has direct band gap of 0.18 eV. It is often alloyed with lead to make lead tin telluride, which is used as an infrared detector material. Tin telluride normally forms p-type semiconductor (Extrinsic semiconductor) due to tin vacancies and is a low temperature superconductor. SnTe exists in 3 crystal phases. At Low temperatures, where the concentration of hole carriers is less than 1.5x10 cm , Tin Telluride exists in rhombohedral phase also known as α-SnTe. At room temperature and atmospheric
Wedding anniversary at the Chicago Public Library. Wedding anniversary A wedding anniversary is the anniversary of the date a wedding took place. Traditional names exist for some of them: for instance, fifty years of marriage is called a "golden wedding anniversary" or simply a "golden anniversary" or "golden wedding". The historic origins of wedding anniversaries date back to the Holy Roman Empire, when husbands crowned their wives with a silver wreath on their twenty-fifth anniversary, and a gold wreath on the fiftieth. Later, principally in the twentieth century, commercialism led to the addition of more anniversaries being represented by a named gift.