Method and system for determining temperature using a magnetic junction

A method for measuring a temperature of magnetic junction switchable using spin transfer, the magnetic junction including a free layer, at least one reference layer and at least one nonmagnetic layer between the free layer and the at least one reference layer, at least one of the at least one reference layer and the free layer including a magnetic layer, the method comprising:

• measuring a temperature variation of a magnetic characteristic of the magnetic layer versus temperature, the magnetic characteristic including at least one of a reference layer coercivity, a shift field, a magnetic anisotropy and an exchange field;
• and
• measuring a bias variation in the magnetic characteristic for the at least one magnetic layer versus an electrical bias for the magnetic junction utilizing a hysteresis loop for the magnetic layer, the step of measuring the bias variation further including:
• measuring a magnetic moment of the magnetic layer for a first plurality of values of an applied magnetic field while a positive electrical bias having a magnitude is applied to the magnetic junction, the applied magnetic field passing through a first coercivity of the magnetic layer and the applied magnetic field increasing in a first direction at least to a saturation of the magnetic layer in the first direction;
• measuring the magnetic moment of the magnetic layer for a second plurality of values of the applied magnetic field while a negative electrical bias having the magnitude is applied to the magnetic junction, the applied magnetic field passing through a second coercivity of the magnetic layer and increasing in a second direction opposite to the first direction at least to the saturation of the magnetic layer in the second direction, the steps of measuring the magnetic moment of the magnetic layer for the first and second plurality of values providing the hysteresis loop for the electrical bias having the magnitude;
• determining a true center for the hysteresis loop;
• repeating the steps of measuring in the first direction, measuring in the second direction and determining the true center for the hysteresis loop for a remainder of a plurality of electrical biases;
• and
• determining the temperature versus the electrical bias for the magnetic junction based on the temperature variation and the bias variation.

A method for measuring a temperature of magnetic junction switchable using spin transfer, the magnetic junction including a free layer, at least one reference layer and at least one nonmagnetic layer between the free layer and the at least one reference layer, the method comprising:

• measuring a temperature variation of a magnetic anisotropy of the free versus temperature;
• and
• measuring a bias variation in the magnetic anisotropy for the free layer, the step of measuring the bias variation further including:
• performing a plurality of spin transfer ferromagnetic resonance (STT-FMR) measurements at a particular temperature for a plurality of electronic biases;
• and
• determining the temperature versus the electrical bias for the magnetic junction based on the temperature variation and the bias variation.