Experimental observation of an anomalous peak in isofield M(T) curves in BaFe$_2$(As$_{1-x}$P$_x$)$_2$ resembling the fish-tail in $M$($H$) curves further suggesting a possible phase transition in the irreversible regime
| Autor: | Salem-Sugui, S., Mosqueira, J., Alvarenga, A. D., S����ora, D., Herculano, E. P., Hu, Ding, Chen, Genfu, Luo, Huiqian |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: | |
| Popis: | We measure magnetization as a function of temperature, magnetic field and time in a BaFe$_2$(As$_{0.68}$P$_{0.32}$)$_2$ single crystal with $T_c$ = 27.6 K. The fish-tail observed on many $M$($H$) curves are used to construct isofield $M$($T$) curves which show an anomalous peak at some temperature $Tt$ suggesting a possible phase transition in the irreversible regime. A vortex dynamics study performed along the peaks evidences a minimum in the relaxation rate occurring at the same position $Tt$ of the minimum value of $M$ in these peaks. A vortex dynamics study performed on $M$($H$) curves show two distinct minimum in the relaxation rate: a first minimum ($H1$) for a lower field correlating with $Tt$ and a second ($H2$) correlating with the peak in the fish-tail. A phase diagram is constructed and the line corresponding to $Tt$ and $H1$ points obey an expression developed in the literature for a structural rhombic to square lattice phase transition, further supporting this view. 11 pages, single column, 5 figures, submitted to Superc. Scien. and Technology |
| Databáze: | OpenAIRE |
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