The radius of the stable points (solid) and the range of the absolute attractive area (dashed) defined as radius of as function of applied field or susceptibility : A field or susceptibility above its critical values or is needed to establish stable points sidewise to the wire and to build up attractive areas. Their extent increases for higher fields and has maximal range a the points . See Fig. 2 for the location of the points mentioned and the attractive area for the case .
Attraction and capturing of particles located on a nonmagnetic substrate for : Magnetic force guides the particles and stabilizes them at the stable points inside the absolute attractive area sidewise to the wire (start position black point, trajectory white line, wire, and substrate gray). Background: The solid line in the contour plot of the potential energy surrounds the absolute attractive area with maximal range at . (Parameters: , , , , , , and ; Contour line space , dark is the low level, and bright is the high level).
Schematic view and placement of brass can: The homogeneous field at the center of the magnet localizes the particles sidewise to a U-shaped iron wire at the end of the quartz bar. The nitrogen gas and the heating wires keep the inner liquid at constant temperature. A detailed description is given in this section.
Brass can with baseplate and thermal components: Several pipes for filling in the liquids allow continuous operating over hours. The metal stripes deduct heat continuously from the can to the liquid nitrogen. A thermostat controlling the heating wires around and at the bottom of the can allow us to establish a stable temperature. The three resistors on the right form the vaporizer. (Detailed description in this section).
(a) Quartz bar with wires fixed to it by a Teflon band: A U-shaped iron wire for localizing particles and a second U-shaped wire with integrated thermocouples is fixed at the end of the quartz bar for monitor the temperature of the inner liquid close to where the attraction occurs. (b) The deposition can for extraction of localized particles is fixed at one end of the base of a U-shaped iron wire.
Brass plate with slots: Placing several or just one particle per slot allows us to observe their torque motion and therefore estimate the lower limit of individually. Thermocouples inserted at the side of the plate ensure an adequate measurement of temperature.
Pulsed field of the magnet measured inside the brass can: A field strength of 54.6 mT within a spread of 5% is reached during a typical loading time of 20 ms. The exponential decay occurs within . The period time and the duty cycle of pulsed fields are limited by these characteristic times.
Localization and levitation of YBCO grains sidewise to a iron wire lifted from ground at 7.5 mT: The iron wire is gold plated for better contrast. Due to the distribution of the susceptibility, localized and levitated grains (white circle) are observed at the same time. The levitation of a grain apart from the wire indicates that its susceptibility is close to the critical value for localization. The temperature at which a grain falls down determines a lower limit of . A movie (Ref. 22) available in the supplementary material shows the picking up, localization, levitation, and falling down of YBCO grains in detail.
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