Month: February 2019

Evaporation Pellets for Thin Film Coating

Gold (Au) Evaporation Materials

Evaporation pellets are evaporation materials for vacuum evaporation coating.

Evaporation is a form of physical vapor deposition (PVD) where the evaporation material is heated to a high vapor pressure, often in a molten state. The vapors are then condensed on the substrate to form a thin film.

The most common heating method for vacuum evaporation is the resistance heating method. The advantages of resistance heating method include simple structure, low cost and convenient operation. The disadvantage is that it is not suitable for refractory metals and high temperature resistant dielectric materials. Electron beam heating and laser heating can overcome the shortcomings of resistance heating. Electron beam heating uses a focused electron beam to directly heat the bombarded material, and the kinetic energy of the electron beam becomes thermal energy, causing the material to evaporate. Laser heating uses a high-power laser as a heating source, but due to the high cost of high-power lasers, it can only be used in a few research laboratories. You can refer to Five evaporation sources for heating for detailed information of the heating methods. As for a thin film precious metal coating, the heating is typically accomplished via resistive heating or by E-beam (electron beam).

Evaporation pellets or slugs are manufactured with specific form factors intended to vaporize at known rates. Often during evaporation processes, “spitting” results in liquid droplet material splattering on to the substrate. Engineered pellets are made with specified metal purities and processes intended to minimize incorporated gases and impurities to mitigate “spitting” in process.

Silver (Ag) Evaporation Materials

Optimal evaporative performance for thin film deposition is highly dependent on the use of high purity materials specifically customized for PVD processes. It requires evaporation materials that feature low organic and inorganic impurities, as well as minimal surface contamination. This level of purity results in highly reproducible performance with low spit rates and defects. SAM offers high-quality evaporation materials in precious metals for your PVD coating.

The following chart shows some common thin film deposition of precious metals. SAM can customize any precious metal alloy you need that is not listed.

 Gold Copper Gold Nickel Gold Nickel Indium
Gold Palladium Gold Gold Silicon
Gold Silver Platinum Gold Tin Gold Zinc
Palladium Rhenium Palladium Lithium Palladium Manganese
Palladium Nickel Platinum Palladium Platinum Iridium
Platinum rhodium Silver Gold Silver Titanium

Please visit https://www.sputtertargets.net/evaporation-materials.html for more information.

Who Discovered Yttrium? | Metal History

Yttrium is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a “rare-earth element“. Yttrium was discovered as early as the 18th century, but it has not been widely used until the last few decades in chemistry, physics, computer technology, film coating, medicine and other fields.

Yttrium History

In 1787, while the Swedish chemist Carl Axel Arrhenius exploring a quarry near Ytterby, a small town near Sweden’s capital city, Stockholm, he discovered an unusual black rock. He thought that he had discovered a new mineral, and sent some specimens to Johan Gadolin, a Finnish mineralogist, for analysis.

During the analysis, Gadolin isolated the yttrium from the mineral. The mineral was later named gadolinite in Gadolin’s honor, and Yttrium was named Ytterby from where the mineral was discovered.

In 1843, a Swedish chemist named Carl Gustaf Mosander studied yttrium samples and discovered three oxides, which were called yttria, erbia and terbia at that time. Currently, they are known as yttrium oxide (white), terbium oxide (yellow), and erbium oxide (rose-colored). A fourth oxide, ytterbium oxide, was identified in 1878.

Yttrium, a transition metal

In the Periodic Table of Elements, yttrium is considered one of the transition metals (yellow in the pic). Other more well-known transition metal elements include gold, silver and iron. The transition metals are the metallic elements that serve as a bridge, or transition, between the two sides of the table. They tend to be strong but pliable, therefore, some of these metals are widely used for wires. Yttrium wires and rods are used in electronics and solar energy. Yttrium is also used in lasers, ceramics, camera lenses, sputtering targets and dozens of other items.

Periodic Table
Periodic Table

Yttrium, a rare earth metal

Yttrium is also one of the seventeen rare-earth elements. The rare-earth elements include yttrium, scandium and 15 lanthanides. They have become indispensible in the manufacturing of cell phones and other technology. Despite their name, rare-earth elements are rather plentiful around the world. Yttrium can be found in most of the rare earth minerals, but has never been discovered in the Earth’s crust as a freestanding element.

Yttrium Properties

Atomic number 38
Atomic symbol Y
Atomic mass 88.906
Melting point 2,772 Fahrenheit (1,522 Celsius)
Boiling point 6,053 F (3,345 C)
Density 4.47 grams per cubic centimeter
State at room temperature Solid

Yttrium Applications

Yttrium metal is used as:

A deoxidizer for vanadium and other non-ferrous metals.

A nebulizer for nodular cast iron.

A catalyst for ethylene polymerization.

Added in small quantities to reduce the grain size in chromium, molybdenum, etc., as well as to strengthen aluminum and magnesium alloys.

Yttrium sputtering target for film coating.

Yttrium compounds have the following uses:

Yttrium oxide is used to produce yttrium iron garnets.

Yttrium oxide is used in ceramic and glass formulations.

Yttrium oxide is widely used for making compounds such as YVO4europium and YVO4europium phosphors in television tubes.

Yttrium iron (Y3Fe5O12), yttrium aluminium (Y3Al5O12) and yttrium gadolinium garnets possess interesting magnetic properties.

Yttrium iron garnets are extremely efficient transmitters and transducers of acoustic energy.

Yttrium aluminum garnet has a hardness of 8.5 and is finding application as a gemstone.

Yttrium oxide sputtering target is used for film coating.

Please visit https://www.sputtertargets.net/ for more information.

How was Chromium discovered? | Metal History

Chromium Discovery

In 1766, the German scientist Johann Gottlob Lehmann analyzed a Siberian ore and determined that it contained lead, which was classified as Siberian red lead.

Louis Nicolas Vauquelin
Louis Nicolas Vauquelin

 

In 1797, a bright red ore was found in the Siberian gold mine. The French chemist Louis Nicolas Vauquelin boiled the mineral with potassium carbonate, and got the lead carbonate and a yellow potassium salt solution of chromic acid. He added a high-mercury salt solution to the yellow solution, and a beautiful red solution appeared; the lead salt solution was added, and a yellowish precipitate appeared; when stannous chloride was added, the solution turned into a crisp green color. He thought that he had found a new metal, which was exactly chromium. The method produces metal chromium.

Chromium can produce beautiful multi-colored compounds: metallic chromium is silvery, chromium sulfate is green, magnesium chromate is yellow, potassium dichromate is orange, chromic is scarlet, and chromium oxide is green, chrome tanning is blue-violet, lead chromate is yellow…Thus Chromium got its name from the Greek word chroma, meaning color, and the chemical symbol is Cr.

Chromium Applications

Chromium was initially used as a pigment. At present, nearly all chromium is commercially extracted from chromite, also known as iron chromium oxide (FeCr2O4).

Chromium was considered to be a component of plants and animals in 1948. It was found to be biologically active in 1954. In 1957, chromium was identified as an essential trace element for animal nutrition. Chromium can act as an enhancer of insulin, affecting the metabolism of sugars, proteins, fats and nucleic acids through insulin.

As a metal element, chromium also has high industrial value. Chromium is widely used in metallurgy, chemical, cast iron, refractory and high-end technology industries.

Chromium sputtering target is an excellent film coating material applied for decorative coating, tool coating, semiconductor coating and so on.

Please visit https://www.sputtertargets.net/ for more information.