Manganese disilicide (MnSi2) is an intermetallic compound, a silicide of manganese. It is a non-stoichiometric compound, with a silicon deficiency expressed as MnSi2–x. Crystal structures of many MnSi2–x compounds resemble a chimney ladder and are called Nowotny phases. They include
MnSi2 (x=0), Mn4Si7 (x=0.250), Mn11Si19 (x=0.273), Mn15Si26 (x=0.267) and Mn27Si47 (x=0.259). These phases have very similar unit cells whose length varies from 1.75 nm for MnSi2 or Mn4Si7, which have almost the same structures, to 11.8 nm for Mn27Si47.[5]
MnSi2–x Nowotny phases have a Mn sublattice with a β-tin structure overlaid with a face-centered cubic Si sublattice. They resemble chimneys of transition metal atoms containing spiraling ladders of Si. These phases are semiconductors with a band gap of 0.4 to 0.9 eV. They exhibit a reasonably high thermoelectric figure of merit ZT ~ 0.8 and have potential applications in thermoelectric generators.[5]
^Shinoda, Daizaburo; Asanabe, Sizuo (1966). "Magnetic Properties of Silicides of Iron Group Transition Elements". Journal of the Physical Society of Japan. 21 (3): 555. Bibcode:1966JPSJ...21..555S. doi:10.1143/JPSJ.21.555.
^Shin, Yooleemi; Rhim, Sung Hyon; Duong, Anh Tuan; Nguyen, Van Quang; Hong, Soon Cheol; Cho, Sunglae; Park, Hyun-Min (2015). "New synthesis of MnSi2 thin film and its thermoelectric properties". Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films. 33 (6): 061516. Bibcode:2015JVSTA..33f1516S. doi:10.1116/1.4932515. ISSN0734-2101.
^ abHiggins, Jeremy M.; Schmitt, Andrew L.; Guzei, Ilia A.; Jin, Song (2008). "Higher Manganese Silicide Nanowires of Nowotny Chimney Ladder Phase". Journal of the American Chemical Society. 130 (47): 16086–16094. doi:10.1021/ja8065122. PMID18983151.