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Register a new userTemperature dependence of antiferromagnetic susceptibility in ferritin
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We show that antiferromagnetic susceptibility in ferritin increases with temperature between 4.2 K and 180 K (i. e. below the N{e}el temperature) when taken as the derivative of the magnetization at high fields ($30times10^4$ Oe). This behavior contrasts with the decrease in temperature previously found, where the susceptibility was determined at lower fields ($5times10^4$ Oe). At high fields (up to $50 times10^4$ Oe) the temperature dependence of the antiferromagnetic susceptibility in ferritin nanoparticles approaches the normal behavior of bulk antiferromagnets and nanoparticles considering superantiferromagnetism, this latter leading to a better agreement at high field and low temperature. The contrast with the previous results is due to the insufficient field range used ($< 5 times10^4$ Oe), not enough to saturate the ferritin uncompensated moment.
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We investigated effects of magnetic field H on antiferromagnetic (AF) structures in CeRh_{1-x}Co_xIn_5 by performing the elastic neutron scattering measurements. By applying H along the [1,-1,0] direction, the incommensurate AF state with the propagation vector of q_{h1}=(1/2,1/2,0.297) observed at H=0 is replaced by the commensurate AF state with the q_{c2} = (1/2, 1/2, 1/4) modulation above 2 T for x=0.23, while the AF states with the q_{c1}=(1/2,1/2,1/2) and q_{h2}=(1/2,1/2,0.42) modulations seen at H=0 change into a single q_{c1}-AF state above ~1.6 T for x=0.7. These results suggest the different types of AF correlation for Co concentrations of 0.23 and 0.7 in an applied magnetic field H.
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