Fig. 3
From: Dimensional crossover in a layered ferromagnet detected by spin correlation driven distortions
Temperature evolution of individual susceptibility tensor elements. The values of the a xxxz, yyyz, b zzzz and c remaining elements of the SHG susceptibility tensor \(\chi _{ijkl}\) at each temperature extracted through simultaneous fitting to all four polarization configurations of the RA data (see text). For every element, a high temperature background derived from the data above T = 150 K was subtracted off. The background subtracted curves (\(\Delta \chi _{ijkl}\)) were then each normalized to their values at T = 7 K. Error bars are the least squared errors of the fits, which are smaller than the data symbols in panel a. Solid lines in panels a and b are the calculated intralayer and interlayer spin correlator respectively. The line in panel c is the function \(\left| {T - T_c} \right|^{ - 2\beta }\), where β is the critical exponent of the magnetization. The two elements zzxx and zzxy are not displayed in c for clarity because their fitted values are very small, resulting in much larger error bars. However their trend follows that of the xxyy, xxzz and yxxx elements shown in c (see Supplementary Note 4). Diffuse magnetic neutron scattering data from CrSiTe3 reproduced from ref. 7 is shown in the inset of a. The inset of b shows the frequency of the Eu phonon (top) and amplitude of the Eg phonon (bottom), which are respectively reproduced from ref. 20 and measured using impulsive stimulated Raman scattering (see Supplementary Note 7)
