Non-magnetic interfaces of LaAlO3/SrTiO3 made by on-axis sputter deposition and the contribution of SrTiO3 substrate

The magnetic properties of interfaces between LaAlO3/SrTiO3 are studied by on-axis sputter deposition at high oxygen pressure. The high pressure sputtering does not induce conductance at these interface, and without conductance, they should not be magnetic either. We find that a possible contribution of SrTiO3 can not be ruled out fully as the bare SrTiO3 substrate also shows a magnetic signal. All interfaces reported in literature grown by either PLD or MBE which are conducing, also have magnetism which arises from the onset of conductivity. If one is missing, the second does too as in the case reported here while SrTiO3 contributes substantially to the conductance of the interface.