The physical properties of two chiral systems with localized and delocalized magnetic moments, Cu₂OSeO₃ and MnSi, are reviewed. It is concluded that the longitudinal fluctuations of magnetic moments affect little the qualitative picture of phase transitions and the magnetic phase diagrams of chiral systems.

Keywords: chiral magnetic systems, phase transitions, longitudinal fluctuations of the magnetic moment PACS: 75.10.−b, 75.10.Lp, 75.30.Kz (all) DOI: 10.3367/UFNe.2016.04.037781 URL: https://ufn.ru/en/articles/2016/9/c/ 000391228000003 2-s2.0-85006154135 2016PhyU...59..866S Citation: Stishov S M "Notes on phase transitions and the role of spin fluctuations" Phys. Usp. 59 866–868 (2016) BibTexBibNote ® (generic)BibNote ® (RIS) MedlineRefWorks PT Journal Article TI Notes on phase transitions and the role of spin fluctuations AU Stishov S M FAU Stishov SM DP 10 Sep, 2016 TA Phys. Usp. VI 59 IP 9 PG 866-868 RX 10.3367/UFNe.2016.04.037781 URL https://ufn.ru/en/articles/2016/9/c/ SO Phys. Usp. 2016 Sep 10;59(9):866-868 Received: 29th, December 2015, revised: 8th, March 2016, accepted: 12th, April 2016 Оригинал: Стишов С М «Заметки о фазовых переходах и роли спиновых флуктуаций» УФН 186 953–956 (2016); DOI: 10.3367/UFNr.2016.04.037781