Data were obtained from the diffractometer DMC at SINQ, PSI, Villigen, Switzerland. 

Experimental set up
lambda = 4.507 A
We used the MA6 vertical magnet with a rotating unit. The window close to the blind
spot was oriented in front of incoming beam, and the angle rotation was done using the
rotating stick.
banana detector with first 2theta at 5 degrees
scans with a3 (omega) from 212 to 132 degrees with 0.2 degrees step. made only 20
degrees diffraction patterns focusing around (110)
slits W14xH30 mm
monitor set to 11500 : about 1mn per a3 angle

Sample
L5xW1.8XH3.2mm. single crystral on Al pin
Sample parameters are the following : a=b=7.05 A, c=3.99 A, alpha = beta = gamma = 90.
The sample is aligned with (100) and (010) in the scattering plane. Magnetic field applied
along (001)

Data treatment
The data at 50K was used as a background (measured with similar statistics), and subtracted
from each of the other. The field protocol (FP) was applied when relevant.

Inset :
Resonant X-ray data  from RESOXS at the end station SIM of the SLS, PSI, Villigen switzerland. 
Cylindrical TmB4 single crystal with (100) and (010) in the scattering plane.
resonant energy of 1461 eV (corresponding to the Tm M_4,5 edge) using linear polarised light. 