An Initial Resistance Versus Magnetic Field Measurement On Ndmo16o44

1234 Words Sep 13th, 2016 5 Pages
An initial resistance versus magnetic field measurement on NdMo16O44 reveals a pronounced magnetic hysteresis effect when a magnetic field is applied perpendicular to the current, but with unknown orientation with respect to the crystal axes, as shown in Fig. 2a for temperatures from 12K to 30K (at temperature below 12K, the overall resistance is too high to produce low-noise measurements with resolvable magnetoresistance features). The individual plots are offset to better show the effect. A sharp drop in the magneto-resistance on the order of 30% of the zero-field resistance appears at a temperature of 12K, with local extrema at fields of approximately +0.38T and +0.55T (-0.38T and -0.55T, respectively) when the field is swept from -3T to +3T (+3T to -3T), with respective features symmetric about H = 0T. The percent change in the resistance of these features decreases as temperature is increased, disappearing above 30K. A positive magnetoresistance feature can also be seen centered at approximately ±0.75T for temperatures of 28K and 30K.. The origin of these magnetoresistance effects is unclear, as NdMo16O44 contains magnetic Nd ions. The paramagnetism associated with Nd-Nd interactions confounds the measurement of the magnetization associated with Mo8-Mo8 interactions―the focus of this paper―resulting in the predominantly paramagnetic magnetic susceptibility behavior for NdMo16O44 shown in Fig. 2b. In contrast, LaMo16O44, demonstrates a more interesting magnetic…

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