Evidence of Point Pinning Centers in Un-Doped Mgb2 Wires at 20 K after HIP ProcessGajda D1,6*, Morawski A2, Zaleski AJ3,6, Häßler W4, Nenkov K1,4, Rindfleisch M5, Cetner T2 and Tomsic M5
- *Corresponding Author:
- Gajda D
International Laboratory of High Magnetic
Fields and Low Temperatures
E-mail: email@example.com, firstname.lastname@example.org
Received Date: March 05, 2016; Accepted Date: March 28, 2016; Published Date: April 08, 2016
Citation: Gajda D, Morawski A, Zaleski AJ, Häßler W, Nenkov K, et al. (2016) Evidence of Point Pinning Centers in Un-Doped Mgb2 Wires at 20 K after HIP Process. J Material Sci Eng 5:244. doi:10.4172/2169-0022.1000244
Copyright: © 2016 Gajda D, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
In this paper we present results of transport critical current density (Jc) at 20 K and 4.2 K, irreversible magnetic field (Birr), upper critical field (Bc2), critical temperature (Tc), pinning force (Fp), scanning pinning force scaling results (Fp/Fpmax and B/Birr) and electron microscope (SEM) images of un-doped MgB2 wires of 0.63 mm diameter. All wires were annealed at pressures ranging from 0.1 MPa to 1 GPa for 15 min between 680°C to 740°C. SEM images show that 1 GPa pressure yields small grains, higher MgB2 material density, and small voids. The results obtained by a physical properties measurement system (PPMS) show that high pressure (1 GPa) and 700°C annealing slightly decreases Tc above 27 K and increases Tc and Birr below 25 K. Un-doped MgB2 wire annealed in 1 GPa for 15 min at 680°C at has a 20 K, 4.5 T Jc of 100 A/mm2 in and a Birr of 7 T. At 4.2 K, this wire has Jc of 100 A/mm2 at 10.5 T. Scaling results show that the dominant pinning mechanism is point pinning for undoped MgB2 wires under 1 GPa pressure and annealed at 680°C (at 20 K).