The highest quality mica V-2 for AFM applications to the Medium Quality (V-4 to V-6) for replication and thin film deposition.
Introduction
EMS Mica Sheets offer a clean surface for EM applications, carbon filming and particle spraying, as well as for AFM applications. There are two types of mica: muscovite and phlogopite. Generally, one differs from the other by color (Muscovite is Ruby, Green or White; Phlogopite is Amber, Yellow, or Silver). The maximum operating temperature for Muscovite is about 500-600°C and for Phlogopite is about 800-900°C. Our line consists of High Quality Muscovite Mica. This mica peels off very thin up to 0.0001" uniform layers, exposing "virgin" mica upon splitting.
Characteristics:
Muscovite, potash type mica, sometimes known as granitic mica, is the best of all micas in dielectric strength, perfection of cleavage, and transparency.
It has the following chemical formula: H2KAI3(Si04)3.
Chemical Composition:
Silica: |
45.5% |
Alumina: |
37.5% |
Potash: |
12.0% |
Water: |
5.00% |
It has a vitreous luster and is colorless to gray, brown, pale green, violet, dark olive green, or rose red. It may be transparent to translucent. It has strong double refraction and is optically negative. It loses water of constitution at 600°C and is practically non-magnetic. It exhibits pleochrism, which is the property of varying in color when viewed from different angles.
RUBY muscovite is harder than green and has a pale brownish red color in thin sheets (0.020") or ruby red in thick plates (0.4"). Ruby mica can be split easily into films of 0.001" or thinner because it has such excellent cleavage. In other colors, this thinness can be obtained but at a considerable risk of cracking.
Physical Properties:
Hardness: Moh's scale: |
2.8 - 3.2 |
Shore's Test: |
80 - 150 |
Specific Gravity, g/cm³: |
2.6 - 3.2 |
Tensile Strength, kg/cm²: |
~ 1750 |
Compression Strength, kg/cm²: |
1900 - 2850 |
Refractive Index (air=1): |
1.56 - 1.60/61 |
Dielectric Strength @20°C in volt/mil: |
3,000 - 6,000 |
Maximum Thermal Resistance: |
625°C (1,157°F) |
Modulus of Elasticity, kgf/cm2E(-3): |
1400 - 2100 |
Optic Axial Angle: |
50° - 75° |
Coefficient of Expansion per °C: |
Perpendicular to cleavage plane 9E(-4) - 36E(-4) |
Calcining Temperature |
700 - 800°C |
Thermal Conductivity: gm.cal/sec/cm2/°C/cm: |
~0.0013 |
Water of Constitution, %: |
4 - 5 |
Moisture Absorption: |
Very low |
Apparent Electric Strength: (0.001-0.003" thick) |
120 - 200kV/mm |
Permittivity @ 15°C (60°F): |
6 - 7 |
Power Factor (loss Tangent) @15°C: |
0.0001 - 0.0004 |
Volume Resistivity @25°C (77°F) 0hm.cm: |
4E(-15) - 2E(-17) |
Acid Reaction : |
Affected by HF |
thickness (mm) |
0.26 - 0.31 |
Quality Determination:
The quality of muscovite mica is verbal determination by visual quality classification ASTM (D351-57T) from the best V-1 to the worst is V-10A.
V-2: Clear and Slightly Stained - Hard, of uniform color, nearly flat and may contain slight crystallographic discoloration, and very slight air inclusions and not more than one fourth of the usable area.
Applications:
In general, for those whom are using mica for the making of carbon support films, thin films coatings research, and some AFM studies where HOPG are used to taking place, the mica V-4 or V-5 is recommended. (Mica must always use freshly cleaved surfaces).
For AFM and SPM calibration, V-1 or V-2 is recommended. However, we believe that it is important that you know what kind of mica is being used in your lab. The information on the mica as given above should be used to make your choice.
Here at EMS, we try to stock a variety of sizes with different thicknesses and classifications of quality for convenience.