Repository logo

Trapped magnetic field distribution above two magnetized bulk superconductors close to each other

Accepted version



Change log


Bulk large-grain superconductors can be used as high-field permanent magnets. Although the properties of such individual trapped field magnets are well documented, much less is known concerning their behaviour when two are brought together. In this work, the interaction between two cylindrical bulk YBa2Cu3O7 (YBCO) superconductors is described. Two sets of experiments were carried out. The first involved the simultaneous magnetization of two bulk superconductors placed a short distance apart. Here, the applied magnetic field was aligned parallel to the c-axis of one bulk, while the other was oriented with its c-axis offset . For a centre-to-centre distance equal to twice the sample height, the presence of the second sample is found not to alter the current distribution inside the first. Consequently, the contribution of both samples simply sums, thus increasing the magnetic flux density between them. In the second set of experiments, the translational approach of the superconductors with parallel c-axes was investigated. The following configurations were considered: (i) face to face approach (with anti-parallel trapped field orientation) and (ii) sideways approach (with parallel trapped field orientation). An irreversible decrease of the trapped field was measured on separation . Repeated approach cycles showed that the irreversible loss of trapped field is largest for the first approach.



bulk superconductor, trapped field magnet, magnetic field gradient, interacting bulk superconductors, flux pinning

Journal Title

Superconductor Science and Technology

Conference Name

Journal ISSN


Volume Title



IOP Publishing


All rights reserved
Engineering and Physical Sciences Research Council (EP/P024947/1)
Engineering and Physical Sciences Research Council (EP/S019367/1)
Engineering and Physical Sciences Research Council (EP/R00661X/1)
Henry Royce Institute (Equipment grant ref. EP/P024947/1) We thank the University of Liege for equipment and travel grants. Michel Houbart is recipient of a FRS-FNRS Research Fellow grant