Mavlyanovite is a
manganese
Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...
-
silicon
Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic tab ...
mineral with formula Mn
5Si
3. It was named after Gani Mavlyanov, an Uzbek geologist who lived from 1910 to 1988.
Transition metal
silicide
A silicide is a type of chemical compound that combines silicon and a (usually) more electropositive element.
Silicon is more electropositive than carbon. Silicides are structurally closer to borides than to carbides.
Similar to borides and carb ...
s represent a rich variety of
intermetallic
An intermetallic (also called an intermetallic compound, intermetallic alloy, ordered intermetallic alloy, and a long-range-ordered alloy) is a type of metallic alloy that forms an ordered solid-state compound between two or more metallic elemen ...
compounds with specific crystal and electronic structures owing to the strong interaction between metals and silicon. Recently, transition metal silicides have gained considerable attention from the scientific community because of their unique
physicochemical properties
Physical chemistry is the study of macroscopic and microscopic phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mecha ...
such as high
thermal stability
In thermodynamics, thermal stability describes the stability of a water body and its resistance to mixing.Schmidt, W. 1928. Über Temperatur und Stabilitätsverhältnisse von Seen. Geogr. Ann 10: 145 - 177. It is the amount of work needed to tr ...
, excellent
electronic conductivity, low
electrical resistivity
Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allows ...
, high strength, good thermodynamic stability, good oxidation, and corrosion resistance. With these favorable properties, transition metal silicides are potential candidates for various
nanotechnological
Nanotechnology, also shortened to nanotech, is the use of matter on an atomic, molecular, and supramolecular scale for industrial purposes. The earliest, widespread description of nanotechnology referred to the particular technological goal o ...
applications such as electronics,
spintronics
Spintronics (a portmanteau meaning spin transport electronics), also known as spin electronics, is the study of the intrinsic spin of the electron and its associated magnetic moment, in addition to its fundamental electronic charge, in solid-sta ...
,
thermoelectrics
Thermoelectric materials show the thermoelectric effect in a strong or convenient form.
The ''thermoelectric effect'' refers to phenomena by which either a temperature difference creates an electric potential or an electric current creates a t ...
, and solar energy harvesting.
Among all transition metal silicides,
manganese
Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...
silicides have been investigated extensively because of their complex structural diversity and fascinating physical properties. Manganese silicides possess seven thermodynamically stable phases, namely: MnSi
1.7 (tetragonal), MnSi (cubic), Mn
5Si
3 (hexagonal), Mn
5Si
2 (tetragonal), Mn
3Si (cubic), Mn
4Si (rhombohedral), and Mn
6Si (rhombohedral). Each of these phases results in different magnetic and thermoelectric properties either in microscopic or microscopic scales. For instance, MnSi is an excellent magnetic contact material for magnetic applications and spintronics such as spin field-effect transistors owing to its simple cubic crystal structure without space inversion symmetry. Among the manganese silicide materials, MnSi
1.7, which is a higher manganese silicide, has attracted most interest in the researches for its excellent thermoelectric properties such as low thermal conductivity (2-4 W/m.K), high Seebeck coefficient (>200 mV/K at ~700 K) and estimable figure of merit (up to 0.7-0.8). Mn
5Si
3 is one of the promising materials for spintronic applications because of its hexagonal structure, and has the potential to create high magnetocrystalline anisotropy with novel spin-electronic properties. In addition, Mn
5Si
3 has a high melting point of 2800 K, indicating that it is a favorable candidate for high-temperature structural applications.
References
{{Silicides
Transition metal silicides