Physical Vapor Deposition: Sputter Coating & Evaporation

Physical vapor deposition processes use vacuum technology to create a sub-atmospheric pressure environment and an atomic or molecular condensable vapor source (from a solid or liquid surface) to deposit thin films and coatings. Sputtering deposition and vacuum evaporation are among the more well known.

physical vapor deposition sputtering evaporation

Sputtering deposition

The sputtering deposition is an etching process that alters the physical properties of a surface. In this process, a gas plasma discharge is set up between two electrodes: a cathode plating material (the sputter coater targets) and an anode material (the substrate). The film made by sputter coating are thin, ranging from 0.00005 – 0.01 mm. Chromium, titanium, aluminum, copper, molybdenum, tungsten, gold, and silver are typical sputter coating targets.

Sputter coated films are used routinely in decorative applications such as watchbands, eyeglasses, and jewelry. Also, the electronics industry relies on heavily sputtered coatings and films, such as thin film wiring on chips and recording heads as well as magnetic and magneto-optic recording media. Companies also use sputter deposition to produce reflective films for large pieces of architectural glass used in the automotive industry. Compared to other deposition processes, sputter deposition is relatively inexpensive.

vacuum coating

Vacuum Evaporation

The vacuum evaporation is a process of reducing the wastewater volume through a method that consists of concentrating a solution by eliminating the solvent by boiling. In this case, it is performed at a pressure lower than atmospheric pressure. Thus, the boiling temperature is much lower than that at atmospheric pressure, thereby resulting in notable energy savings. The basic components of this process consist of: evaporation pellets,  heat-exchanger, vacuum, vapor separator, and condenser.

Vacuum evaporation is used in the semiconductor, microelectronics, and optical industries and in this context is a process of depositing thin films of material onto surfaces. High-purity films can be obtained from a source evaporation material with high purity. The source of the material that is going to be vaporized onto the substrate can be a solid in any shape or form (usually pellets). The versatility of this method trumps other deposition processes. Also, when the deposition is not desired, masks are utilized to define the areas on the substrate for control purposes.

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Smelting Technology of Metal Titanium and Titanium Alloy

In the industrial production of titainum and titanium alloys, the most commonly used techniques are vacuum arc remelting (VAR) and cold hearth melting.

Vacuum Arc Remelting

VAR technology can refine the ingot structure in titanium alloy smelting and improve the purity of the product. The main developments of this technology in recent years are as follows:

  • Fully-automatic VAR re-dissolution process

Advanced computer technologies are applied to VAR processes. For example, automated electronic control box data collection systems can establish excellent smelting modes for specific ingots and alloys. In addition, it can analyze the problems in the smelting process and improve the metal yield.

  • Ingot size enlargement

Large VAR furnaces can smelt titanium ingots with a mass of 30t. At present, the tonnage of vacuum self-consumption arc furnaces for molten titanium is mostly 8-15t.

  • Different power supply methods

The power supply mode adopts a coaxial power supply mode, which can cancel the magnetic field and prevent segregation.

  • Development of numerical simulation technology

Domestic and foreign scholars have made some progress in using the numerical simulation method to study the VAR process. The distribution law of the ingot temperature field has been successfully explored and a model for predicting the solidification microstructure, ingot composition and defect distribution has been established.

Cold hearth Melting

Cold hearth melting uses a plasma (Plasma Arc) or an electron beam (Electron Beam) as a heat source, and can be divided into two processes of plasma cold bed furnace and electron beam cold bed furnace smelting. Electron beam cold-hearth melting has many advantages over vacuum arc melting:

1 Various forms of raw materials such as residual materials, loose titanium sponge and titanium shavings, and economical raw materials can be used;

2 It can remove high-density impurities such as molybdenum (Mo), tungsten (W) and tantalum (Ta), low-density impurities such as cyanide and volatile impurities, and is an important technology for pure titanium alloy materials;

3 Improve the yield of metals by producing ingots of various cross-sections.

Information from Stanford Advanced Materials (SAM) Corporation, a global sputtering target manufacturing company.

Pure Metal Sputtering Target: Silver Sputter Target

About Pure Metal Element Silver

Siver is a very malleable metallic chemical element with atomic number 47 that is capable of a high degree of polish, has the highest thermal and electric conductivity of any substance. Silver sputtering target is used as decorative coatings and antibiotic coating in medical devices.

Silver Sputtering Target Specification

SAM Sputter Taget

Product Silver Sputtering Target
Brand Stanford Advanced Materials
Category Pure Metal Sputtering Target
Material Type Silver
Symbol Ag
Atomic Number 47
Color/Appearance Silver, Metallic
Melting Point 962 °C
Theoretical Density 10.5 g/cc

Available Sputtering Target Dimensions

A comprehensive range of sizes of SAM’s sputtering targets are available to accommodate the requirements of most popular deposition tools.

silver sputtering target different dimensions

  • Disk targets, column targets, step wafer targets, plate targets
  • Rectangular targets, slice targets, step rectangular targets
  • Tubular targets / rotation sputtering target

Available Silver Sputter Target Purity

99.9% (3N), 99.95% (3N5), 99.99% (4N), 99.999% (5N), 99.9995% (5N5), 99.9999% (6N)

Silver Sputtering Target Applications

Physical vapor deposition (PVD) of thin films, laser ablation deposition (PLD), magnetron sputtering for semiconductor, display, LED and photovoltaic bonding

Each target can be designed to fit customer specified backing plates or cups with either indium/tin or silver epoxy bonding.  Bonding service is available on oxygen free copper backing plate.

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Basic Knowledge of Refractory Metal Tantalum

Tantalum Overview

Tantalum is part of the refractory metal group and it has good physical and chemical properties.

Tantalum has high hardness that can reach 6-6.5. Its melting point is as high as 2996 ° C, only after carbon, tungsten, rhenium and osmium. Tantalum is malleable and can be drawn into a thin foil. Its coefficient of thermal expansion is very small, and it only expands by 6.6 parts per million per degree Celsius. In addition, it has a strong toughness and is superior to copper.

Refractory Metal tantalum
Refractory Metal Tantalum

Tantalum does not react with hydrochloric acid, concentrated nitric acid and “aqua regia” under both cold and hot conditions. And tantalum is only corroded by concentrated sulfuric acid at temperatures above 150 °C. Tantalum can be considered one of the most chemically stable metals at temperatures below 150 °C. It is also highly resistant to corrosion because of the formation of a stable tantalum pentoxide (Ta2O5) protective layer on its surface.

Tantalum Application

Tantalum can be used to manufacture evaporation vessels, as well as tubes, rectifiers, and electrolytic capacitors. Tantalum forms a stable anodized film in an acidic electrolyte. The electrolytic capacitor made of tantalum has the advantages of large capacity, small size and good reliability. Tantalum capacitors are the most important use of tantalum, around 2/3 of the full use of tantalum. Tantalum is also the material for making electron-emitting tubes and high-power tube parts. Anti-corrosion equipment made by Tantalum is used in the chemical industry such as strong acid, bromine and ammonia producing industries. The metal tantalum can be used as a structural material for the combustion chamber of an aircraft engine. Tantalum is easy to form and can be used as support accessories, heat shields, heaters and heat sinks in high temperature vacuum furnaces. Tantalum can also be used as orthopedic and surgical materials. Tantalum sputtering targets and tantalum evaporation materials are important coating materials in physical vapor deposition.

tantalum capacitor
tantalum capacitor

High Purity Tantalum Preparation

The chemical inertness and relatively low price of tantalum make it a good alternative to platinum.  However, high-purity tantalum is not easy to get because it is always found together with niobium in the mineral groups of tantalite, columbite, and coltan. To get high purity tantalum, here are several methods.

1 Tantalum powder can be obtained by metal thermal reduction (sodium thermal reduction) method. The potassium fluotantalate is reduced with sodium metal under an inert atmosphere: K2TaF7 + 5Na-→Ta+5NaF+2KF. The reaction was carried out in a stainless steel tank, and the reaction was quickly completed when the temperature was heated to 900 °C. The powder prepared by this method has irregular grain shape and fine particle size, and is suitable for making tantalum capacitors.

2 The tantalum powder can also be obtained by molten salt electrolysis: a molten salt of a mixture of potassium fluoroantimonate, potassium fluoride and potassium chloride is used as an electrolyte, and tantalum pentoxide (Ta2O5) is dissolved therein and electrolyzed at 750 °C. This method can obtain a bismuth powder having a purity of 99.8 to 99.9%.

3 Tantalum can also be obtained by carbothermal reduction of Ta2O5. The reduction is generally carried out in two steps: first, a mixture of a certain ratio of Ta2O5 and carbon is made into tantalum carbide (TaC) at 1800 to 2000 ° C in a hydrogen atmosphere. Then, TaC and Ta2O5 are prepared into a mixture in a certain ratio, and reduced to tantalum in a vacuum.

4 Tantalum can also be obtained by thermal decomposition or hydrogen reduction of chloride. The dense metal crucible can be prepared by vacuum arc, electron beam, plasma beam melting or powder metallurgy.

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Multiple Applications of Silver

Medical uses of silver

Silver is used in many medical applications due to its antibacterial properties. Most medical devices, such as bandages, wound cleansers, catheters, pacemakers, valves and feeding tubes, that comes into contact with the body contain silver. The hospital also uses silver in air ducts to prevent certain conditions, such as Legionnaires Disease.

Silver for textiles

The thermal and biological properties of silver make it an ideal choice for the commercial textile industry. Silver is used in the anti-microbial properties of high-end sportswear to inhibit the growth of bacteria that can cause odors. Traditionally, silver and gold threads have been woven into clothing.


Silver for food and water

Silver will play an important role in the food industry in the next decade. The US Food and Drug Administration has approved the addition of silver to bottled water to help kill bacteria, which opened the door for major municipalities to use white water for clean water at local communities, cities and state levels. Silver tip cutting tools are used for meat processing. It is also used in the processing of milk, cheese making and baking.

Silver superconductor

Another important use of silver is as a superconductor, mainly for large industrial and military electric motors. For a while, silver was used as a strategic reserve for military applications.

Other applications of silver

In addition to the above aspects, silver has many other uses. Silver is used as a wood preservative. Silver sputtering targets and silver evaporating materials are used for vacuum coating. The silver coating plays a key role in the solar power industry. Solar cells coated with silver absorb light and convert it into electricity.


From the perspective of industrial applications, the future of silver is indeed very obvious. Many industrial applications will continue to use silver, and many new applications for silver will continue to grow at a significant rate.

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Molybdenum Application for Metallurgy

Molybdenum, a silvery-grey metal, does not seem to be as popular as tit anium, aluminum, and platinum. But it is actually a very widely used metal in our life. Today, we will introduce the application of molybdenum in metallurgy.

Molybdenum in Metallurgy

Steel Metallurgy

The main use of molybdenum for metallurgy is to produce various types of steel and alloys. The addition of molybdenum (mainly in the form of ferromolybdenum, molybdenum oxide, and calcium molybdate) to a range of steels such as structural steel, spring steel, bearing steel, tool steel, stainless steel, and magnetic steel can significantly improve the properties of steel.


Molybdenum improves the hardenability, toughness and heat strength of steel and prevents temper brittleness. It also improves the corrosion resistance of steel to certain media so that it does not pit. In addition, adding molybdenum into the cast iron enhances the strength and wear resistance of the cast iron.

Nonferrous Metallurgy

In non-ferrous metal alloys, molybdenum can be alloyed with metals such as nickel, cobalt, ruthenium, aluminum, and titanium. These molybdenum alloys are used in the electronics, electrical industry, and machinery industries to make filament and tube parts for light bulbs; they can also be used to make parts such as electromagnetic contacts, gas engine blades, valve protection, and electric furnace resistance.

nickel molybdenum alloy
Nickel Molybdenum Alloy

Molybdenum can improve the heat resistance and corrosion resistance of non-ferrous alloys and is an important element of nonferrous metallurgy.

Metal Processing

Molybdenum and its alloys can be used in a variety of molds, cores, perforated bars, tool holders and chill plates for metalworking.


Tools made of molybdenum can improve the processing speed and feed rate of metal processing, reduce the wear and deformation of metal parts, and thus extend the service life of the workpiece. These tools can also be used to machine large-sized parts and improve the accuracy of the workpiece.

Resistance welding electrodes made of molybdenum can be used for electronic brazing and welding of copper, brass and other materials with high thermal conductivity.

The molybdenum tip has a long service life and does not contaminate the workpiece, so it is suitable for processing electronic products.

Molybdenum can be used to make test dies for steel samples, which is very durable.

In addition, some metals require high temperature treatment in hydrogen, inert gas or vacuum, and molybdenum boats are ideal containers for holding such metals.

Molybdenum Boat
Molybdenum Boat

SAM Sputter Targets Corporation is a global evaporation material and sputtering target manufacturing company. Please visit for more information.

Working Mechanism of Pulsed Laser Deposition

Pulsed laser deposition (PLD) is a physical vapor deposition (PVD) technique where a high-power pulsed laser beam is focused inside a vacuum chamber to strike a target of the material that is to be deposited.  Although the equipment of pulsed laser deposition (PLD) system is simple, its working mechanism is related to many complicated physical phenomena. It includes all physical interactions between the laser and the substance when the high-energy pulsed radiation strikes the solid sputtering target, the formation of plasma plumes and the transfer of the molten material through the plasma plume to the surface of the heated substrate. Therefore, PLD can generally be divided into the following three stages:

Interaction between laser radiation and the sputtering target

In this stage, the laser beam is focused on the surface of the target materials. When sufficient high energy flux and short pulse width are achieved, all elements of the target surface are rapidly heated to the evaporation temperature. At this point, the material in the target will be sputtered from the target. The instantaneous melting rate of the target is highly dependent on the flow of laser light onto the target. The melting mechanism involves many complex physical phenomena such as collisions, heat, excitation with electrons, delamination, and fluid mechanics.

Dynamics of molten matter

In the second stage, according to the law of aerodynamics, the sputtered particles have a tendency to move toward the substrate. The space thickness varies with the function cosn θ, and n>>1. The area of the laser spot and the temperature of the plasma have an important influence on the uniformity of the deposited film. The distance between the target and the substrate is another factor that affects the angular extent of the molten material. It has also been found that placing a baffle close to the substrate narrows the angular extent.

Deposition of molten material on the substrate

The third stage is the key to determining the quality of the film. The high-energy nuclides emitted hit the surface of the substrate and may cause various damages to the substrate. The high energy nuclide sputters some of the atoms on the surface, and a collision zone is established between the incident stream and the sputtered atoms. The film is formed immediately after the formation of this thermal energy zone (collision zone), which is the best place to condense particles. As long as the condensation rate is higher than the release rate of the sputtered particles, the heat balance condition can be quickly reached, and the film can be formed on the surface of the substrate due to the weakened flow of the molten particles.

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Holmium Oxide Introduction (Properties & Applications)


Holmium oxide is a chemical compound of rare-earth element holmium and oxygen with the formula Ho2O3. Together with dysprosium oxide, it is considered one of the most paramagnetic substances known. Holmium oxide is one of the constituents of erbium oxide minerals. In the natural state, holmium oxide often coexists with trivalent oxides of lanthanides, and we need special methods to separate them. Holmium oxide can be used to prepare a glass of a particular color. The visible absorption spectrum of Ho2O3-containing glasses and solutions has a series of sharp peaks and is therefore traditionally used as a standard for spectroscopic calibration.


Appearance  Light yellow or yellow powder, belonging to the equiaxed crystal yttria type structure
Density (g/mL, 25 ° C)  8.16
Melting point (° C)  2415
Boiling point (° C, atmospheric pressure)  3900
Solubility  insoluble in water, soluble in acid
Chemical reaction  Ho2O3+ 6 NH4Cl → 2 HoCl3+ 6 NH3+ 3 H2O


It is used to manufacture new light source xenon lamps, and can also be used as an additive for yttrium iron obtained from yttrium aluminum garnet and to prepare metal holmium. Holmium oxide can be used as a yellow and red colorant for Soviet diamonds and glass. Glass containing holmium oxide and holmium oxide solution (often perchloric acid solution) have sharp absorption peaks in the spectrum of 200-900 nm, and thus can be used as a standard for spectrometer calibration and have been commercialized. Like other rare earth elements, cerium oxide is also used as a special catalyst, phosphor, laser and coating material (sputtering targets & evaporation materials).

Holmium Oxide (Ho2O3) Sputtering Target

Holmium oxide sputtering targets

Holmium oxide sputtering targets with the highest quality can be used in semiconductor, chemical vapor deposition (CVD) and physical vapor deposition (PVD) applications. Stanford Advanced Materials (SAM) Sputtering Target Manufacturer offers target bonding service, reclaim service and customized service, which can help you make full use of the coating materials.

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Gadolinium Oxide Products (Powder & Coating Materials & Microcrystal )

Rare earth oxides (REOs) have gained more and more attention due to their unique magnetic, luminescent, and electrochemical properties. They are used for applications in various industries such as nuclear, electronics, lasers, and etc. Among them, although Gadolinium oxide (Gd2O3) is not the most widely used REOs, but is the most researched one.

The key property of Gadolinium Oxide

Chemical formula Gd2O3
Molar mass 362.50 g/mol
Magnetic susceptibility +53,200·10−6 cm3/mol
Density 7.41 (g/cm3)
Melting Point 2330  (°C)

Gadolinium oxide preparation

Gadolinium oxide can be formed by thermal decomposition of the hydroxide, nitrate, carbonate, or oxalates. Specifically, first, use monazite or a mixed rare earth ore as the raw material. Then Extract and purify the ore to prepare the samarium-gadolinium mixed rare earth solution. Use oxalic acid to precipitate gadolinium oxalic acid. Then separate, dry, and burn the gadolinium oxalic acid to obtain gadolinium oxide.

Gadolinium oxide powder

Gadolinium oxide is a white powder. It is insoluble in water but soluble in acid. It easily absorbs moisture and carbon dioxide from the air. It can be used as a raw material for various fluorescent compounds, absorption material in atomic reactions, nuclear fuels, magnetic bubble material, screen-sensitivity increasing material, as well as many other applications in the chemical, glass and electronic industries.

Gadolinium Oxide (Gd2O3) Powder
Gadolinium Oxide (Gd2O3) Powder

Gadolinium oxide sputtering target

Gadolinium oxide sputtering target is the product made of gadolinium oxide materials by casting or powder metallurgy. Common shapes of the gadolinium oxide sputter targets are planar, circular, rotary, and rectangular. In general, planar targets are cheaper but rotary targets have a higher utilization rate. Gadolinium oxide sputtering target is specially used in the sputtering process (a method of physical vapor deposition) to form a film on the substrate of glass, metal or other materials. Its purpose is either to protect the substrate or improve its properties.

Gadolinium Oxide (Gd2O3) Sputtering Target
Gadolinium Oxide (Gd2O3) Sputtering Target

Gadolinium oxide microcrystal

Gadolinium oxide microcrystal is defined as the gadolinium oxide nanomaterial with at least one direction usually in the range of 1–100 nm. These materials have different physical, chemical, and electrical properties in comparison with traditional bulk gadolinium oxide materials. These nanomaterials have the crystallographic stability up to temperatures of 2325°C, high mechanical strength, excellent thermal conductivity, and a wide band optical gap. Thus, they are used for new products and applications and may also be incorporated into various industrial processes in the nuclear industry, electronics, lasers, and optical material.

Gadolinium Oxide (Gd2O3) Nanomaterial
Gadolinium Oxide (Gd2O3) Nanomaterial

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Who discovered Iridium? | History of Metal


Iridium, a very hard, brittle, silvery-white transition metal of the platinum group, is the second-densest metal (after osmium) with a density of 22.56 g/cm3 as defined by experimental X-ray crystallography.



Smithson Tennant

Smithson TennantIridium was discovered together with osmium in1803 by English chemist Smithson Tennant in London. When crude platinum was dissolved in dilute aqua regia (a mixture of nitric and hydrochloric acids), it left behind a black residue. Because of the black color, it was initially thought to be graphite. By treating it alternately with alkalis and acids, Tennant was able to separate it into two new elements. These he announced at the Royal Institution in London, naming one iridium (comeing from the Latin word ‘iris’, meaning rainbow) because many of its salts were so colorful; and the other osmium (derived from osme, the Greek word for smell) because it had a curious odor.


Name Iridium
Symbol Ir
Color silvery-white
CAS number 7439-88-5
Melting point 2446°C, 4435°F, 2719 K
Boiling point 4428°C, 8002°F, 4701 K
Density (g cm−3) 22.5622


Iridium is a rare, hard, lustrous, brittle, very dense platinum-like metal. Chemically it is almost as unreactive as gold. It is the most corrosion-resistant metal known and it resists attack by any acid. Iridium is generally credited with being the second densest element (after osmium) based on measured density, although calculations involving the space lattices of the elements show that iridium is denser.


Due to its good corrosion-resistance, it is used of as a hardening agent for special alloy or to form an alloy with osmium, which is used for bearing compass and tipping pens.

Iridium Application

Iridium is used in making Iridium crucibles and other equipment that is used at high temperatures. Iridium sputtering target is a coating material to produce Iridium film, which is used as protective film or heavy-duty electrical contacts. In addition, Iridium was used in making the international standard kilogram, which is an alloy of 90% platinum and 10% iridium.

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Reference: “Iridium.” Chemicool Periodic Table. 17 Oct. 2012. Web. 3/21/2019 <>.