What technique did Minato use to separate the Kyuubi into two parts? When the Kyuubi attacked the Leaf Village after being hypnotized by Tobi, Minato as a last resort separated the Kyuubi into two parts. Recently in the latest chapters of the manga, it looks like the Kyuubi was separated into Black and White, as in Evil and Good, or Yin and Yang.

What technique did he use? Did he really split the Kyuubi into good and evil halves? Or is it just something made up for the split?
Minato used the Death Reaper Seal to seal the Yin half the Kyuubi in him, then he used the Eight Trigram Seal combined with the 4 Element Seal to seal the Yang Half of the Kyuubi in Naruto.

From Naruto Wiki


  During its attack on Konoha, Minato Namikaze sacrificed his life by
  splitting the fox's chakra into two: sealing the Yang half within his
  son and sealing the Yin half within himself.




Lower down in the page:


  Since Kurama's chakra was too immense to be sealed within an infant
  like Naruto, Minato first used the Dead Demon Consuming Seal to
  separate and seal its Yin half within himself and then prepared the
  Eight Trigrams Seal to imprison the Yang half within Naruto


The 4 Element Seal was used so that the chakra of the Nine Tailed Fox would slowly leak out from the Eight Trigrams Seal and merge with Naruto's own chakra.