This book is devoted to the special characteristics of an important element of lanthanides chemistry: Europium. It presents the technological aspects of Europium in many fields of industry as well as in fundamental analysis by using a new, safe and low cost methodology. This book discusses the many applications for the Europium element either in its metallic or ionic state. These applications are in the fields of (1) optical sensors for pesticides, biological molecules such as proteins, peptides, nucleic acids, hormones, and drugs, (2) manufacturing of portable computers, communication equipments and consumer electronic products, (3) manufacturing of optoelectronics devices such as visible lasers that can be grown on Si substrates, (4) preparation of photocatalysts for degradation of vehicle exhaust gases and water pollutants, (5) manufacturing of photonic materials, (6) manufacturing of magneto optic-memories and modulators that are applied to biological detection of proteins, DNAs, and other materials leading to practical use in various diagnostics, (7) synthesis of chemically inert materials resistant to radiation damage to protect civil aerospace, military structures and aircraft, and (8) the preparation of highly luminescent materials for biomarkers.