The anhydrous solid trehalose: low-temperature EPR study of glassy and boson peak modes

Kveder, Marina; Šarić, Iva; Merunka, Dalibor; Jokić, Milan; Valić, Srećko; Rakvin, Boris (2013) The anhydrous solid trehalose: low-temperature EPR study of glassy and boson peak modes. Journal of Non-Crystalline Solids, 375 . pp. 19-24. ISSN 0022-3093

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Abstract

Electron spin-lattice relaxation times ( T1 ) were measured by X- band electron paramagnetic resonance (EPR) spectroscopy in irradiated trehalose glass (TR-G) and trehalose-β crystalline state (TR-C) from 5 – 290 K. Throughout the whole temperature interval studied a consistently shorter T1 was observed in TR-G than TR- C while the largest difference was detected below ca. 80 K. Here, the theoretical analysis within the soft potential model pointed to the two mechanisms responsible for a more efficient energy exchange between the spin system and the lattice in TR-G: the thermally activated dynamics of glassy modes and the Raman process with boson peak (BP) modes. In this context, the glassy polymorph of anhydrous trehalose corroborates the idea that the boson peak, being a universal property of amorphous/disordered solids, can be studied by EPR even at X- band frequencies. It is further suggested that the mechanisms, involving glassy/soft/BP modes, which provide additional channel for the electron spin coupling with the lattice in glassy as compared to the crystalline state, could be proposed as a universal phenomenon aiming to explain the electron spin relaxation in disordered matrices at temperatures above a few Kelvin in general.

Item Type:	Article
Uncontrolled Keywords:	glassy state; electron spin-lattice relaxation time; boson peak; SPM
Subjects:	NATURAL SCIENCES > Physics NATURAL SCIENCES > Physics > Condensed Matter Physics
Divisions:	Division of Physical Chemistry
Projects:	Project title Project leader Project code Project type Molekulska struktura i dinamika sustava s paramagnetskim česticama- Marina Ilakovac-Kveder 098-0982915-2939 MZOS Samo-udruživanje u gelovima i sinteza funkcionalnih hibridnih materijala- Leo Frkanec 098-0982904-2912 MZOS Strukturne i dinamičke promjene u sustavima makromolekula- Srećko Valić 062-0000000-3209 MZOS
Depositing User:	Marina Ilakovac Kveder
Date Deposited:	17 Apr 2019 11:00
URI:	http://fulir.irb.hr/id/eprint/4492
DOI:	10.1016/j.jnoncrysol.2013.05.016

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