Demonstration of efficient spin injection and detection into p-Si using NiFe2O4 based spin injector in NiFe2O4/MgO/p-Si device

The injection of spin-polarized electrons from a magnetic material into semiconductor is currently one of the foremost challenges in semiconductor spin electronics. Here, we have studied the efficient electrical spin injection and detection from nickel doped Fe3O4 (NFO) into the p-Si having (100) crystal orientation via MgO thin insulating tunnel barrier with the help of three-terminal Hanle measurement. The NFO/MgO/p-Si heterojunction has been prepared using pulsed laser deposition (PLD) technique. Clear Hanle and Inverted Hanle signals have been noticed in spin injection and detection condition of the heterojunction. A large value of Hanle signal (Delta V=2.4 mV) has been detected at room temperature (300 K). Pure spin accumulation in p-Si resulted from spin injection from strong ferromagnetic NFO via MgO tunnel barrier has been corroborated by a meticulous experiment incorporating a non-magnetic Ag/MgO/p-Si heterostructure. The bias dependent Delta V and spin lifetime (tau) suggest that the transport of the heterojunction is governed by the spin tunnelling via pin-hole free MgO tunnel barrier. Hence the oxide magnetic materials establish a decent platform in spin injection and detection for the development and improvement of room temperature spin-based electronic devices.

Automated summary

In this study, efficient electrical spin injection and detection from NFO into p-Si via MgO tunnel barrier was achieved and proved to be promising. The use of oxide magnetic materials in spin injection and detection for room temperature spin-based electronic devices has been demonstrated.