Magnetic tunnel junction devices are provided. A magnetic tunnel junction device includes a pinned layer. The magnetic tunnel junction device includes a free layer on the pinned layer. The free layer includes a first layer, a second layer that is on the first layer, and a third layer that is between the first layer and the second layer. A Curie temperature of the third layer is lower than a Curie temperature of the first layer and lower than a Curie temperature of the second layer. Moreover, the magnetic tunnel junction device includes an insulating layer that is between the pinned layer and the free layer. Related magnetoresistive memory devices are also provided.